Swipely, cool but scary?

So there's this rather cool new service that says they will find and give you special deals to the stores and merchants you use already. The way they do it is to examine your credit card bills and help you find deals. They say:

With Swipely, you can earn automatic cash back rewards at the best local places Boston has to offer. There are no coupons to cut, vouchers to buy or loyalty cards to forget - with Swipely you earn valuable rewards on every purchase with the credit or debit cards you already have, automatically. Best of all, Swipely is free!

Sounds great, but you know how they do it? You have to give them your credit card info and login to the credit card company web site, so they can look at your charges. They say it is very secure:

Swipely downloads transactions to give you rewards via our banking technology partner using a secure, read-only connection trusted by more than 5,000 banks and 26 million consumers. Swipely uses 256-bit SSL EV bank-grade encryption and SAS 70 Type II secure data centers.

I am pretty promiscuous when it comes to this kind of thing (for example, I've been using Mint.com for a while now) but still this one creeps me out just a little bit. What do you say?