RetailMeNot (NASDAQ:SALE) is well positioned to be a big winner this holiday shopping season, but the leader in digital coupons isn't alone. There are plenty of surprising companies suddenly gunning for RetailMeNot's business, and it remains to be seen how the shakeout will play out. 

Groupon (NASDAQ:GRPN) became the latest player to toss its hat into the couponing ring, announcing the introduction of Freebies late last week. Groupon Freebies offers digital coupons, promotion codes, sales, giveaways, and samples from online retailers and brands. The daily-deals leader still saw its shares tumble 15% last week, but that was mostly due to insider selling rather than the push to diversify. Freebies is launching domestically now, with an international push slated for next year.

This isn't the first time that the flash-sale niche has tried to rip a page out of the RetailMeNot playbook by consolidating merchant-backed promotional codes. LivingSocial -- the (NASDAQ:AMZN) backed site that's second in popularity to Groupon -- introduced a similar marketplace of coupon codes this summer. 

It's easy to see why Groupon and LivingSocial want in. Shoppers have tired of the novelty of flash sales. Revenue at Groupon rose a mere 5% in its latest quarter, and that's with a push to start selling more physical goods, offering more business services, and the launch of its Pull marketplace inflating top-line results.

LivingSocial doesn't trade publicly, but updates its financials with every quarterly filing. LivingSocial continues to lose money, and its revenue of $384 million through the first nine months of this year is essentially flat with the $387 million it rang up during the first nine months of last year.  

It's not just the daily-deals websites. American Express (NYSE:AXP) has been pushing cardholders to "connect" their plastic to leading social-media websites to take advantage of coupons and savings available through the synced interface. 

RetailMeNot may not necessarily be worried about American Express, LivingSocial, and now Groupon invading its turf. There is still the networking effect working in its favor as consumers flock to the site because it has the most coupon codes. The site and mobile app attracted 132 million visits this past quarter. Merchants will naturally want to play nice with RetailMeNot, striking commission-generating relationships to make sure their offers are being communicated effectively.

Everyone wants to be RetailMeNot this holiday shopping season, but there really is only one RetailMeNot.