I usually got between 12 to 75 spam comments per day (often MORE). Akismet stopped all of them, but I had to manually "delete all spam". This got annoying and I looked for a plugin to solve this problem.
I'm the sort of person that likes installing as little as possible: on my laptop, desktop, websites, everywhere. Once extracted, this plugin was just A SINGLE PHP file spanning just 4.7K (excluding the README).
After installing this plugin, and 3 days later, I have not received a single spam.
This is a fantastic solution, because it does not get in users's way, or in the webmaster's way. It is small, efficient, and works perfectly!
Thanks for this!