I have developed 2-3 Facebook apps so far, and can't afford the Facebook CPC program to promote my app.

I signed up 2 free facebook promotion network, 1 of Applifer. However they rejected my application and said my app is not a game? (!!) Anyone has successfully joint them with a non-game app?

I then applied another network called Appcastnet , which accepts me instantly. They said they provide 1:3 Exchange Ratio and it is very useful for small apps (like those of mine). I don't have much traffic to start with and want to know if their claim works.

I also posted few posts in different forums, which also attracts some users.

Any other ideas which you think is useful for small developers to promote apps? Is there any newsletter or user groups I should also consider?

Why not use facebook to promote?

Create a page about your company and advertise youe app there??
Use other social media sites like Twitter to create awareness.

Start a blog? Write about your experiences in developing the app. Stuff like how easy or difficult it was to do what you did.

Hope that helps a little.

Good Luck

I would suggest both. As i have both and both are very beneficial in their own way