If a picture is worth a thousand words, perhaps a video--which is really a string of pictures--is worth an entire book.

Entrepreneurs think so. Many have jumped into video with both feet. More than 1.9 billion users log in and visit YouTube each month, according to YouTube. A chunk of them are entrepreneurs trying to market their products and services. Should you join the crowd?

Yes, but if you don't do it carefully, you can easily spend a lot of money, waste a lot of time and get frustrated beyond measure.

"Video is fire," says business communications expert Steve Washer. "It can burn and destroy when we lose control of it. But when we understand its nature and align with its power, miracles can happen."

Washer is the video whiz behind Chris Haroun, the top-rated professor on the online learning platform, Udemy. Haroun, a former Goldman Sachs banker, made several million dollars in under three years on his Udemy videos, including his popular class, An Entire MBA in 1 Course.

Should you be on video?

"Quite simply, anyone with a product or service that needs to be explained should consider video," says Washer, CEO of Visible Authority, a Windsor, Conn., consulting firm, who also writes a blog about video marketing for business owners. "And you definitely should be on video if you need to demonstrate how you are different from your competitors."

Despite the ubiquity of video, many business owners still haven't figured out how to make it work for them. Washer spoke with me recently about the most common misconceptions about video marketing.

1. You can shoot a video once and then forget about it.

Video is a medium you use to build a relationship with your customers. There is no better vehicle to educate them in an entertaining way.

Consider producing a video series that explains the nature of the ecosystem that surrounds and supports your value proposition. And put yourself in the video so your product has a friendly, passionate advocate.

2. It's a slam-dunk. Just go on video and say what you want to.

Video shows exactly who you are to the world each moment you appear in it. The truth is in every electron that is sent down the wire, through the air and into someone's smart phone.

So you must understand who you are, accept it consciously, and align yourself with the qualities you want to share with the world--before anyone hits the record button.

Certain savants do all this without thinking. The rest of us, not so much. There are very few naturals when it comes to being on video.

Practice a lot. It is time well spent.

3. Video is an inherently superior form of marketing.

Video viewership is actually falling on YouTube, Facebook and Instagram. Simply translating print ideas into video is not only ineffective--it's a losing proposition.

Don't try to copy other people. And beware of "best practices." They don't have meaning for a creative endeavor like video. Beyond straight-up technical quality, anything goes.

Be passionate and entertaining. In the early days of Internet video, Gary Vaynerchuk ate dirt on the Wine Library and Tom Dickson of Blendtec ground up an iPhone in a series that went viral. Countless YouTube stars sell make-up, promote comedy gigs and push weight-loss products. The most successful way to use video is to provide constant exposure to good ideas. This is what generates trust and goodwill--and more business.

4. Advertising is the best use of video.

Thinking that advertising is the way to control your destiny is twisted "me-first" thinking. It does not work. Commercials are ignored.

Instead, always put your viewers first. Solve problems for them in videos that clearly demonstrate how something is done, and they will invite you into their world--rather than expel you from it as fast as their finger can swipe right.

5. Video is expensive.

The price for video technology has dropped dramatically. Yes, you can spend thousands, but you don't have to.

Invest in a good microphone (a wired one will cost about $200, and a wireless one twice that), a good webcam (an adequate one will be $50 or so) and good LED lighting (a pair of lights will run you less than $100). You can set up a low-cost video studio for your business at home.