I have been receiving a lot of comment spam. I would say around 30 comments a day. I wanted to try the simplest option possible, so I created a hidden field in the comment form that only a bot would fill out. This was working under the assumption that bots don’t read css. This worked for a little while.
My spam had been reduced to under 10 comments a day, which was still high, but maintainable. As time went on, it crept back up to 30 or more a day. The next step was recaptcha, which was a breeze to set up.
For two days now, my comment spam has totalled a big goose egg. 0.