Mr Sun Studios - All about Design, Programming and Game Development.

If you use 125×125 ads on your blog or website, then Performancing Ads might be for you. They provide a service which lets you sell your ad space at a fixed price for a weekly fee. You can also sell the more common different sized banners if you are able to make it into the [...]

Be patient. Sponsors are very busy people and it will take time before they might even see your sponsorship request
Use flashgamelicense.com. They provide a free service that gives you an oppurtunity to show your game to potential sponsors and/or developers. I use it and highly recommend it
E-mail as many sponsors as you can, even if [...]