Here’s an example of a profitable business built on the back of twitter. Twitpic is doing more than $1.5 million in ad sales a year, with 70% profit margins. They never raised any funding either.

A great example of a side project that turned into a nicely profitable business, the link has the full interview which is well worth listening to.

From the original interview on mixergy:

Link

“- In 2009, the site did over $1.5 million in ad sales

– For every million in sales, the company keeps $700,000

– The site has about 6.5 million registered users

– Noah was recently offered 8 figures for the business

– There are only 4 people working on the site (including Noah’s parents)”