The idea of an increased bid seems reasonable, since the Yahoo discussions didn't work out. Also, Google had $33.4 billion in cash, cash equivalents, and marketable securities just sitting around as of September 30th, so the company can afford to pay a little more.
Saving money has become a popular activity, and Groupon is among the top players in the field. Its ties to Facebook and Twitter, along with its mobile presence, then add additional value. There is one major issue in a possible Google purchase of Groupon because more regulatory scrutiny by the federal government over its power online.
See this Amp at http://amplify.com/u/fpm0