The Constant Contact Developer Challenge is a chance for developers of all sizes to use to create cool apps that integrate with Constant Contact & give them the chance to win up to $15,000 in cash.

Apps have to leverage Constant Contact’s APIs in innovative ways that ultimately will help small businesses and non-profits work.

The contest runs until October 31st 2010, so you’ve got some good lead time!

Here are 5 things you need to know:

1. Free to enter
2. Long lead time
3. The chance to enter in multiple contest categories
4. You keep the rights to your final code – so you can market/sell your app
5. We’ll help promote winning apps via press & media

Sweet!

And, don’t forget the fabulous prizes:

You’ve got to check it out!