Hey Pappy,
If you get going with this please let us know how it works for you, but I'd be leery of any service where you're at their mercy to contact your "list". Yeah, email has it's share of deliverability problems, but I'd rather take my chances with a real email list instead of trusting a service I know nothing about.
I do think almost any business can use email to their advantage and restaurants especially, but be careful what kind of coupons you encourage people to pass around, as you wouldn't want to repeat the fiasco Starbucks went through earlier this year
http://www.seedsofgrowth.com/the-sta...sco-venti-size
I'd take some lessons from California Tortilla
http://www.geolocal.com/public/79.cfm?sd=45 who's got a nice list of over 6000 folks they market to on a regular basis.
Good luck!
Steve