We recently asked the same question of a number of startups as we wanted to write an article on it, but struggled to get enough to share. I can tell you one big name SAAS product (one you would all know) admitted they converted 2% of traffic into paid accounts. For the record they had a 30 day free trial as their freemium offer.

If you want our data, check out our post we wrote recently here:

http://www.eventarc.com/posts/2010/05/18/conversion-statisti...