Many apps and services have emerged to promote other apps to their customer base.  This is great if you can get featured at a reasonable rate.  But as the network of users grows and the supply of apps that want to be promoted grows, the rate the network can charge will grow as well.  There’s a constant negotiation going on behind the scenes as networks try to get the best content to attract users but also charge the highest rates possible to acquire that content.  So shop around.

Here are some example programs:

• App-o-Day: Free App Deal of the Day
• Free App A Day – The best paid apps for free daily – FreeAppADay.com
• Amazon