It's very easy to build and sell software. It's not very easy to sustain, maintain it and support a large number of users.
A free product like this is going to attract a ton of totally unskilled and unqualified users (translation = people who won't make many sales). Anyone giving up 30% of their revenue who actually has good sales coming in is going to expect a certain level of customer service - a very high level. And it's not going to take them long to realize instead of giving up 30% they can license software for a fraction of that and keep an extra 20% or more of their revenue.
