No, for two reasons.

First, Humble Bundle scales. They can pull together a handful of artists to offer some MP3s, and sell it to the whole world. Groupon has to negotiate with small businesses in every market that they want to have a presence.

Secondly, the nature of the goods on offer is different, in that a restaurant or cafe has considerable marginal costs associated with each sale, whereas a comedian selling MP3s has no marginal costs, and even the Humble Bundle team has almost no marginal costs. The Humble Bundle team spends a few cents on bandwidth for each sale, and the artist only loses hypothetical future sales at a higher price.

(edit: pluralized "business")