My two sponsored games were both from contests so that's a bit different. I do remember way back when I tried to get my first game sponsored (it was crap) - It either took over a week to get shut down or they didn't respond to me at all, I can't remember - making me not very helpful, sorry
All of mine have been contest entries and not formal sponsorships. Though I can tell you from experience that Dan responds within about three days if he's interested, and he may respond a while later or never at all if he isn't interested.
If you're looking for a sponsor and can't seem to get feedback then I would recommend trying FlashGameLicense.com - it's a new site that lets developers post their games in a place where multiple sponsors can view and bid on it, getting sponsors to look at your games, and not the other way around.
This is sort of a related question to this thread so I'll just ask it here: If you want to get sponsored, do you just submit it with the "submit" link at the top of the page or what?
I know this is a question a newbie would do (im a newbie so who cares?) but how works the sponsors system? they give u money? or support and help? and what they win giving u money for the game? the copyright? thanks a lot xP