Marc Andreessen explained the use of those metrics on Rap Genius:

“As someone who was in the room as an observer at the Groupon board when the decision to use these metrics was made, I think Groupon was honestly trying to provide additional information that investors would find useful, which mirrored the way management thought about running the business.

However, no good deed goes unpunished, and widespread media paranoia about business metrics still lingering from the 2000 dot com crash combined with other missteps on Groupon’s part combined to make the use of those non-standard metrics highly controversial and ultimately negative for the company.”