I think starting anything in the coupon space is difficult as it's not about the technology, it's about the sales. Groupon has an extremely simple website...it is merely a platform to display the deals: their success is essentially totally driven by the massive sales force they have at work them.

I think that technology in this space will play a greater role in the future (mobile, targeting, etc.) but for now the winners are those who sign up the most businesses and the most consumers.

I don't think the author should give up on startups entirely; it sounds like they have indeed learnt some skills and can apply those to any number of future projects. At least they have worked out this space is not for them!