John, that depends a lot on who is your target market and what kind of market (clientele) your business operates in.
Here in S.F. , as far as I know, I have not been affected by them at all. Business has been very good. However, I serve a niche market.
Occasionally, I get one of the ex- Groupon clients that was really pissed off at the service they got. So, in a sense, it is almost like free advertisement for me.
On the other hand, I guess I don't get to know or hear from the ones that did get a good service and stuck with that company.