Groupon. Living Social. Ideeli. RueLaLa. These are just a few of the most prominent daily deals sites that have taken couponing from a hobby your frugal great-aunt cherished to the movement that’s flooding inboxes around the country.

Bucking predictions that they would fade as the economy recovered, AP reported that Groupon has seen its ranks swell from 2 million subscribers to 85 milllion in the past year and a half. And D.C.-based Chinatown has gone from 120,000 subscribers to 28 million. Facebook and Google are getting in on the social side of daily deals, too, with services set to build on their existing coupon offers.

Those top two sites pull in big business, and with Groupon’s IPO expected any day, Living Social is also eyeing expansion.

“You’re really in a position where somebody acquires you or you become a public company. I think either of them could happen with us,” Living Social Chief Executive Tim O’Shaughnessy told Reuters.

(O’Shaughnessy is the son-in-law of The Washington Post Co. Chairman Donald Graham.)

And sites are scrambling to get in on the next big wave in social deals — instant deals.

Groupon started testing out Groupon Now, its real-time mobile deals app, in Chicago earlier this month. LivingSocial launched a similar service for D.C. customers this year.

How do you use daily deals sites? Do you subscribe to more than one?

Related stories:

Groupon launches Groupon Now pilot in Chicago

Living Social offers $1 lunch menu for D.C. customers

Our ad­ven­ture into social eating