They are; from the rules [1]
6. ENTRY CREDITS. All eligible entrants who submit a qualified Entry will receive a credit of $25 USD (approximately 17 EUR) to be used toward Paid Services from AWS (does not include Amazon FPS). Individual credit codes valued at $25 USD (approximately 17 EUR) will be emailed to such entrants following the announcement of the Grand Prize winner.
[1] http://aws.amazon.com/startupchallenge/rules/
edit: formatting
Don't kid yourself that you have a chance to win, but spend 10 minutes filling out the app to save $25. Not a bad deal.