>> but there are plenty of groupons for niches, also. >> yes. >> the restaurant guy did something really interesting, which is he did the math, which said, you know, if i do a 50% -- let's say i do $50. >> he just made it -- >> that was the average check size is bigger, even if that customer never returns he's going to be profitable. >> to your original point, this is just another marketing channel, and so you run your numbers, you get your roi, makes sense for some people. not for others. thanks so much you guys. books on being more effective in business are a dime a dozen. but here now are five books that could change the way you think about managing. courtesy of "time" magazine. the e-myth revisited, why most small businesses don't work and what to do about it by michael gerber, argues that technical skills alone aren't enough. he says effective management skills, and vision are also necessary to become a successful business owner. the one minute manager by kenneth blancheard and spencer johnson offers simple advice to