Benji Smith is presenting 30 ideas (one each day) on his site. He’s currently at number 8 or so. You should read the relative post, 30 days: 30 ideas for his reasons.

Obviously Benji believes it’s the implementation and not the idea that matters.

So, I knew some bloggers make lots of money from AdSense (and other ad systems) and thought this was a business model for blogs and content sites.

Then I read the blog of PlentyOfFish.com owner. PlentyOfFish is (yet another) dating site, only it’s completely free. There are no paid memberships! All revenue is based on AdSense: check this post for a photo of a $900,000 (nine hundred thousand) check for 2 months and this post on how the business grew (in general it’s a very interesting blog).

I find it amazing you can make $5.5 mil / year from AdSense alone (and I guess PlentyOfFish has other advertising programs). I would still hesitate to do something similar, but it certainly shows it can lead to success.

Akismet is a service by the team behind Wordpress, that analyzes a comment and tells you if it’s spam or not.

The corresponding Wordpress plug-in (included in Wordpress 2.0) works great: I have disabled every other anti-spam plug-in I was previously using, and Akismet has caught ~500 spam comments (with only 1 going through).

The nice thing is you can use it for your application (just get an API key and a library for your language of choice). There are 3 licenses, including a commercial one.

Being a service has one big advantage: the system learns from many sources (thousands of blogs), so if a new kind of spam message is used (e.g. one resembling natural language and with few links) the system will learn quickly (because you don’t have to do all of the training yourself).

I’m wondering if the same system or one like it could be used for emails and whether it would be better to use that instead of building a custom solution…