Groupon really started something. Everybody and their brother – from Facebook (News - Alert) to Rediff.com India Ltd. – is lining up to follow in the company’s footsteps.

Facebook today announced in a blog its new Deals on Facebook offer. Building on the Check-In Deals it unveiled a few months ago, Deals on Facebook offers discounts on “fun experiences to share with your favorite people.” The service initially is available Atlanta, Austin, Dallas, San Diego, and San Francisco.

“We've worked with partners and local businesses to help deliver the best social activities in your area,” according to the Facebook blog. ”And once you've found a deal you like, having the deal on Facebook makes it easy to share, buy and plan with your friends. 

“For example, Austin City Limits Live is offering an 'All Access Experience' for concerts starting in May. You can buy this deal and get backstage passes, sound check access and a catered dinner in addition to attending the show,” the Facebook blog explains.

A similar service was launched today in 40 cities in India by NASDAQ-listed company Rediff.com, whose websites already reach 15 million online visitors per month. The company calls its new Deal Ho Jaye service “the first Groupon-type service to reach abroad.”

It “will help consumers discover new services and experiences in their city, such as restaurants, spas, hotels, healthcare, tattoos, hobby classes, adventure sports and other local attractions across 70 categories and at 30 to 60 percent  discounts, thus helping them make the most of their quality time with their family and friends,” according to Rediff.com.

“This is the beginning of an industry. Groupon has fundamentally uncovered something,” says John Shave, the founder of former telecom outfit Globalcom (News - Alert), whose latest venture is a Groupon competitor called bidmyway.com. The bidmyway.com services will be available in 10 cities nationwide initially, with Chicago and Milwaukee the first to go live.

Company management and an investment vehicle called Four Directions Holdings Co. that Shave controls provided the initial $1.315 million in funding for bidmyway.com. The online portal plans to complete a second round of funding in midsummer. And Shave estimates that bidmyway.com will be generating gross revenues of more than $21 million after 12 months in service, and exceed $150 million after its first 10 markets go live.

It’s no mystery as to why so many companies are lining up to follow Groupon’s lead.

As Ben Horowitz, a co-founder of venture capital firm Andreessen Horowitz, noted in a recent New York Times article: “There’s never been a company ever that has grown as fast as Groupon or Facebook, because no one could reach such a big audience so quickly.” He goes on to say that “the ability to build a company that gets to $1 billion in revenues in less than two years is unprecedented.”