Anybody who runs an online directory or blog will know about the pitfalls of spam, and will know how ruthless spam bots can attack your site, usually promoting porn, pharmaceuticals, or pyramid selling "get rich quick" scams.

When attacked by robots, the volume of spam can be quite overwhelming - bringing your site down at worst, and at the very least, introducing an unnecessary source of frustration.

At AdStorm we run a handful of directories, such as the Accounting Software directory, and the Marketing Agency directory. (Feel free to add your listing, by the way) .  All of these have at various times been the subject of attacks from spam bots, so we looked into the field of human verification software to make sure a real person is submitting info to the sites. We found that Captcha was an easy, free software to install. There are pre-existing plugins for Wordpress and MediaWiki, and a php version that's easy to use.  We have now managed to virtually eliminate the problem of spam on our websites.