There will always be people who scour coupon sites for deals, even taking into account natural customer churn. It's conceivable that Groupon could be the Google on coupon hunting.
However the number of coupons available isn't going to increase forever, and may well already be in decline (for some measure of businesses using Groupon compared with deals offered).
This is because those businesses see Groupon as a way to infrequently attract a large number of people to try their products at a price that they would not be able to sustain for other marketing models such as advertising.
The only way Groupon can "grow" is to continually reach new businesses to ensure that the number of coupons available is high. However, eventually the well will run dry.
However the number of coupons available isn't going to increase forever, and may well already be in decline (for some measure of businesses using Groupon compared with deals offered).
This is because those businesses see Groupon as a way to infrequently attract a large number of people to try their products at a price that they would not be able to sustain for other marketing models such as advertising.
The only way Groupon can "grow" is to continually reach new businesses to ensure that the number of coupons available is high. However, eventually the well will run dry.