If using on-line databases always seemed too much trouble for too little payoff, now is a good time to reconsider their merits. Three recent trends -- a dramatic increase in data available, ease of use, and "dedicated" software packages designed for specific databases -- make these compilations of business and financial data more valuable than ever before.

Consider these statistics. Last fall, 1,350 databases were available from 213 on-line services; this fall there are nearly 1,800 offerings from 270 on-line services. And the number is growing by about 35% annually, according to Carlos A. Cuadra, president of Cuadra Associates Inc., publisher of the quarterly Directory of Online Databases (see "How to Find the Database You Need," page 214).

About half of these new databases are related to business and financial topics, with most of the remainder containing specialized technical information that could even the odds for smaller companies vis a vis their larger competitors. "A sizable portion of the English-speaking world's printed information is already indexed or abstracted in databases," says Steven Sieck, director of the Electronic Information Program at Link Resources Corp., a New York City organization that keeps tabs on the industry.

Whether you want to identify new markets, spot important developments in existing ones, analyze the competition, or even compare your operating ratios with those of your competitors, there is, in all likelihood, a database that will help do the job.

Here are some of the more recent and useful entries:

Dun's Market Identifiers, produced by Dun's Marketing Services, a company of The Dun & Bradstreet Corp., contains the names, addresses, and phone numbers of 1.5 million business establishments with $1 million or more in sales. Listings also identify the type of business, the year the company was founded, whether it has single or multiple locations, sales volume and number of employees, and the names of the executive officers and directors. Using this database, a British financial-services company seeking to expand, for instance, was able to count in 20 minutes every New England company from $1 million to $25 million in sales. Directory of Companys will soon be available from Pergamon-InfoLine, and will contain similar information as Dun's Market Identifiers on English companies. Electronic Yellow Pages, which contain the Yellow Pages from nearly every U.S. city's telephone book, can also be useful to companies developing new markets.

Trademarkscan, which contains 600,000 registered and pending trademarks, can help make a quick first cut when considering new names for products or businesses.

Textline abstracts economic and business news from most major European newspapers. It can be particularly valuable for checking out overseas companies, since its summaries of foreign-language news stories are written in English.

Lexpat, from Mead Data Central, gives the full text of U.S. patents issued since 1975. Recently, a manufacturer that was considering developing a motorcycle helmet fitted with a two-way radio searched Lexpat to see if the idea had previously surfaced. He found that three or four people had taken out patents on similar devices. Quick calls to the inventors ascertained that their brainchildren were available for licencing.

NewsNet is a vendor that has put about 200 specialized newsletters on-line. Gaetano J. Tata, owner of a five-person video production company in Davie, Fla., uses the service weekly for keeping up with events in his industry and ferreting out news of grants available to independent TV producers. Since some of the newsletters he is interested in cost as much as $800 a year, he figures that the $50 to $75 he spends a month is a real bargain.

The Computer Database, which debuts this month, will abstract articles from more than 500 computer-related publications and will provide valuable information for companies developing or marketing computer-related products.

In the jargon peculiar to the database world, producers, or "information providers," compile databases; vendors, or "information utilities," sell the finished products to end users -- although sometimes the lines between the two get blurred.

Producers, which can be nonprofit or for-profit, differ in how they serve up their data. PTS Time Series and PTS Forecasts, produced by Predicasts Inc., in Cleveland, for instance, are a combination of bibliographic and factual databases, since they extract annual statistics on industries from thousands of published sources. The Department of Commerce produces a so-called full-text database, Commerce Business Daily, which announces federal procurements and contract awards, and is simply an electronic version of the Department's print ed daily. Then there are factual databases, such as the U.S. Bureau of Labor Statis tic's Producer Price Index, which gives wholesale price levels for approximately 6,000products.

Finally, there are bibliographic databases, such as Management Contents, which indexes and abstracts articles from more than 700 business publications. You have to order the original from the publisher, a library, or a document delivery firm. (Management Contents, as it happens, also delivers.)

Individual databases may be available through one vendor or several. Management Contents, for instance, is offered by Dialog Information Services Inc. and System Development Corp. (SDC), among others. A note of caution: Some vendors offer only partial databases. The Source, for example, a consumer service that is not particularly useful for serious business research, lists Management Contents in its catalog, but provides an abbreviated version with only 28 magazines. Most of the major vendors, however, deliver a full set of goods (see "Major Business Database Vendors," page 212).

Vendors generally charge on a pay-as-you-go basis: You are assessed only for "connect time," the minutes you are actually on-line. That fee usually ranges from $50 to $100 per hour for business databases, although a few vendors will collect a sign-up fee of about $50. Some, like Dun's Market Identifiers, one of the more expensive at $100 an hour, also charge an additional sum -- Dun's is $1.00 to $1.50 per company name (depending on format) -- for each item that you retrieve. The procedure for signing up with a vendor is simple: After filling out an application, you are assigned a password, and are ready to go.

Although databases were once designed primarily for trained researchers and were, accordingly, cumbersome to use, increasingly vendors are targeting their wares toward novices. Some of the older services, however, still require some effort to use effectively. With Dialog, for example, which markets one of the most valuable collections of business databases, you need a day or two to master an intricate and extensive set of commands. But the vendor, like many others, offers training courses. (A one-and-a-half-day session from Dialog costs $135, but includes free connect-time.)

By contrast, NewsNet, which has been on the market for only a year, supplies multiple-choice menus, which make searching easy to learn. But there is a trade-off. You may request information from a service such as Dialog's in many more formats than is possible with vendors using less complicated structures.

Most database searches are conducted by using key words. Eugene P. Schonfeld, for instance, chairman of Schonfeld & Associates Inc., a management consulting firm in Evanston, Ill., was asked by a client for help in handling the layoff of 100 people. The CEO was particularly interested in finding out what severance benefits other businesses in similar situations had offered. Schonfeld connected to Dialog, asked to see several databases, including Management Contents, and typed in "layoff" and "severance."

Within about 20 minutes, his computer had printed out summaries of nearly 100 articles on layoffs involving severance benefits. Schonfeld then chose the most pertinent ones and phoned Management Contents for photocopies. He paid about $30 for on-line time and $10 for each article delivered.

A number of vendors offer more efficient search methods. For instance, instead of looking at each of Dialog's databases separately, you can ask whether your key words or phrases appear in any of several databases. Dialog will let you know the number of relevant citations in each. You can then decide which databases to examine more carefully.

Then there is "selective dissemination of information," or SDI, as it is known in the database trade. SDI is a time-saving feature for those who consistently look for the same types of items. Video producer Tata, for example, used SDI (which NewsNet calls NewsFlash) to request NewsNet to store in memory the key words, "cable" and "video." Now, whenever he logs on, the service automatically shows him headlines for any new articles containing those two words.

Early this year, the Institute for Scientific Information (ISI), in Philadelphia, a producer and vendor of scientific databases, introduced Sci-Mate Universal On-line Searcher ($440), a software package that speeds up and simplifies searches on ISI, Dialog, BRS, SDC, and Medline, a vendor of medical databases.

The menu-driven program automatically dials up any of these vendors and logs you on. It then leads you through a number of choices, translating your responses into commands the database service can understand. So instead of giving the command, T 2/5/1-10, on Dialog, say, you would simply be asked how many articles from an individual search you wanted to read. With a companion software package, Personal Data Manager ($540), you can compile information that you have retrieved into a personal file, which can be searched exactly like an on-line database. (ISI sells both programs for $880.)

Probably the most exciting new database-related software packages are those that let you down-load information, then provide a means to manipulate the data off-line. Currently, only a handful of these programs -- which also facilitate logging on and searching -- are available, but more are on the way.

Disclosure Inc., in Bethesda, Md., for example, which maintains a database of Securities and Exchange Commission filings made by publicly held companies, offers a program called MicroDisclosure ($250), which works with Dialog. You can select companies by location, product, financial criteria, and the like. Then you can down-load the income statements for a number of companies directly into such spreadsheets as VisiCalc and Lotus 1-2-3, go off-line, and analyze the data. Several programs designed for use with Dow Jones News/Retrieval Service are also on the market. The Dow Jones Market Analyzer ($349) uses the service's daily price and volume figures to create charts of a stock's general movements.

Michael Youngblood, a vice-president and funds-investment officer at Texas Federal Savings & Loan in Dallas, uses another dedicated program, VisiLink ($250, from VisiCorp), to retrieve financial information from Lexington, Mass.-based Data Resources Inc.'s (DRL) business and financial databases. (Lotus Development Corp., Cambridge, Mass., has plans to link its 1-2-3 program with another business database vendor, ADP Network Services in Ann Arbor, Mich. [see INC., November, page 197].)

Once a week, at a cost of about $75, Youngblood instructs VisiLink to call DRI and connect to the Yield Spread Analyzer, a DataKit, which is one of several preselected packages from DRI's full database. He tells the program which day. he is interested in, and the software automatically retrieves statistics on Treasuruy bill interest rates, rate spreads among securities, and related data. The information is then loaded directly into a VisiCalc template, so Youngblood can analyze it offline. "It used to take me hours to do this by hand," he says. "Now it's automatic."