tedster - 3:39 am on Sep 3, 2011 (gmt 0)
There is a flood of coupon sites these days. I think you're going to need a major innovation to get Google to rank you well. Otherwise, yes - your site will bang smack into a ranking problem.
And I don't think a noindex meta tag on the coupon page alone is going to give you the edge you want. If I had an innovative idea for a coupon site, I'd probably be building it myself.