You've created a website with killer design, sophisticated structure to support SEO, and an elegant e-commerce engine. And what do you get for all that work? Some amount of sales, of course, but also bots. Lots and lots of bots. Some are bad, some are good, but if you don't know it's happening, you may not correctly conduct and interpret your marketing efforts.

According to Web security company Incapsula, bots can account for up to 61.5 percent of all website traffic. Only 38.5 percent was human. That's even more exaggerated from last year, when the company found that 51 percent of traffic was from bots and 49 percent from humans.

The bot traffic breaks out as follows (all percentages are of total traffic, not of bot-only traffic):

  • 31 percent search engines and other "good" bots
  • 5 percent site scrapers that pull information off websites, including email addresses, for ultimate use in spam targeting and reverse engineering of pricing and business models
  • 4.5 percent hacking tools to steal credit card numbers, attack sites, hijack servers or sites, or deface websites
  • 0.5 percent spam to create link farms back to their own site, post malware links, or post content on blogs or forums that will annoy customers
  • 20.5 percent "other impersonators" that are "unclassified bots with hostile intentions"

The company analyzed 1.45 billion site visits over a 90-day period. Data came from 20,000 sites on Incapsula's network, which probably means a non-representative list of sites. Maybe they are particularly prone to bot traffic. Then again, maybe the mix isn't that unusual. With bot traffic up by 21 percent year over year, it's disturbing.

Forget, for a moment, the good and bad bot division. Don't concern yourself with malware, spam, and the other variations that can be so annoying. Instead, consider how you interpret metrics for your website.

Traffic is a big one. You look at the inbound, see what sticks, what doesn't, where it goes, and what you can deduce about interests and intentions from that. But close to two-thirds isn't human. How much of your analysis assumes that you get three times the number of people than you actually do?

You need to filter out the bot traffic to see the real impact of marketing, search engine ads, copy and design, promotions, conversion tactics, and what have you. If you don't filter, you run the danger of making wrong decisions about investment, efforts, design, merchandising, and a host of other things.