Agreed. I don't really see a tech angle to this story, other than the fact that it's a website...
Was Groupon widely covered by the tech press? That's not my recollection but I could be mistaken. One could perhaps question whether Groupon deserved the coverage it got as a "tech company", but that doesn't mean other online retailers should necessarily be covered by the tech press.
[1] The nature of the "hack" itself used digital media (email, digital coupons). The main breakthrough seems more of a social/business/marketing hack than anything uniquely driven by hard tech programming or engineering, though. Although I could be corrected on this latter point by someone with specific knowledge.
[2] Part of the story was very high growth and market penetration. There was much "its different this time" type discussion about how this was all enabled by technology.