Full disclaimer: I’m FMTC’s CTO and product manager for FMTC’s Publisher Toolkit. I don’t pay for my access (but would if I didn’t get it for free).
FMTC aggregates, verifies, standardizes and adds meta data to coupons and deals from over 10,000 merchants and provides that data via API to enterprise customers. But FMTC’s Publisher Toolkit gives that same data to publishers and bloggers at a fraction of the price (starting at $7.99 / month).