1. An overload of customers they cannot handle especially right before the coupon is set to expire from it's inflated value.

There isn't a business in this world that has ever (seriously) complained about having too many customers.

2. Coupons are generally used to build customer bases. Because the customers are loyal to Groupon, they aren't interested in the restaurant itself, just the deal they got from Groupon. Thus the advertisement does nothing but give them even less money to make and little to no repeat business.

Anything that gets a customer in the door is a good thing. Every customer that comes through the door is a customer who might become a repeat customer. You could argue over the relative effectiveness of Groupon versus other advertising methods (and advertising is exactly what this is), but to say that Groupon in and of itself has no value (in fact, you imply that it has NEGATIVE value) to a business is ridiculous.

I've got a 2004 Mazda3 and I can tell you that it doesn't have a line-in. I wish.

I remember about 10 years ago I was doing a co-op stint at a division of a large company doing a mix of programming and system administration work. At some point, I found myself in the company of the head of the division after having just solved some dinky little problem with his PC. There was another guy in the room at the time and after I worked my magic the division head looks over to the other guy in the room, points to me, and says "Our vo-tech guys really do a great job".

Interesting. I was on vacationing in London 2 years ago and decided to snap some casual photos in the Underground while waiting for my train. A police officer noticed me take the picture and only told me that the use of flash was not permitted. She didn't tell me that I could not take pictures (no tripod was being used).