LISNews has been running on Drupal for about a year now. Before that we ran on Slashcode for a few years, before that it was PHPSlash for a couple years, and even before that I did it all by hand. If you run (or read) blogs you know comment spam is a big problem. If all you do is run or read a blog you actually have NO idea just how bad it really is. I'd estimate about 80% of all POST requests to all the LISHosted sites are spammers. When I have LISNews on the LISHost servers I worked hard at fine tuning the mod_security rules to combat spam.
Within hours of moving to Ibiblio I could see they have very different rules, and I'd need to do something else. I'm actually surprised just how good my rules were working. So I turned on CAPTCHAs. I tried some images, reCAPTCHA, Math, and finally the basic text CAPTCHAs to fight spam. They also worked. A few weeks ago I got a complaint that the CAPTCHAs were getting in the way. This wasn't the first time, so I thought I'd try something new, I turned to Mollom.
I was shocked that within a day the number of comments went up. It's been a few weeks now, and I continue to be shocked at the number of comments we're seeing. Mollom is doing a decent job blocking spam, but more importantly it's letting more people comment. The bad guys are kept out (for the most part) and the good guys have a very low hurtle to get over. (Or at least I think so. If the current trend holds, then I'll be convinced that it is indeed Mollom and not just a coincidence). Two charts that illustrate what I'm seeing on this end