While they'll probably continue to acquire customers indefinitely for the near future, the question remains whether, once they've captured adequate market share

While they'll probably continue to acquire customers indefinitely for the near future, the question remains whether, once they've captured adequate market share/some sort of saturation point, they can really improve their customer retention through much better targeted deals, and perhaps, some sort of user engagement on their site. In theory, at some point when they stop acquiring customers, if they can have good user engagement and therefore retention, they'll cut out a large chunk of their costs (customer acquisition marketing) and still have their user base that draws revenue. Whether Groupon can pull this off, with ever growing competition, is the question on everyone's mind.