With Groupon and LivingSocial leading the pack, daily deal sites are one of the hottest businesses out there right now, so it is probably no surprise that several hundred eager entrepreneurial types packed in for the Daily Deal Summit in New York City Wednesday.

Although LivingSocial, which just landed $400 million in venture capital and whose CEO is expecting to see $1 billion in revenues this year, joined the panel discussions, Groupon, the Chicago-based startup that started the deal craze was conspicuously absent, although it sent a rep, according to summit organizer Jay Weintraub, who estimated about 500 attendees showed up for the summit, about twice the number that had preregistered.

As one moderator, Tolman Geffs, managing director of investment banking firm The Jordan Edmiston Group, joked: “If everyone would please just say, it: 'I envy Groupon?'”

The audience might have envied the fastest-growing Internet company—and it's chief rival—but no one can deny that they all face the same challenges in their business models. Here’s a look at some of the key topics:

Consumer fatigue

With the rising number of daily deal companies and the deluge of emailed offers, are consumers getting tired or jaded when it comes to deals? Panelists said no, at least not yet, and that their businesses are still growing, with email remaining the prime medium through which to offer deals.

Jake Maas, senior vice president of business development for LivingSocial, which is now in 200 markets in 12 countries and boasts 26 million members, said that the key to combating a backlash is giving consumers something unexpected.

"The space has always been about surprising users with interesting deals and interesting offers and deals of value," he said.

Nathan Richardson, president of Gilt City, a sister site to fashion flash sales site Gilt Groupe, which is now in seven markets, said the site’s email open rates and its levels of consumer interest are still on the rise, although Gilt City differs in that it doesn’t send deals everyday. “We’re not contacting them on a daily basis, we’re contacting them when we have relevant offers,” he said.

Others acknowledged that the space may be getting a bit crowded, and if the novelty hasn’t worn off yet, it could soon. “We don’t see [consumer fatigue], but we’re planning for it,” said Jed Nachman, vice president of sales and client services at Yelp, pointing out the overflowing crowd. “Look at this room, look at this space.”

It's all about personalizing the deal

Andrew Moss, the founder and chief strategy officer of BuyWithMe, said that as his company develops, its strategy evolves into contacting "the right consumers, from the right merchants, at the right time.” To deliver on that vision, he is focusing on personalizing offerings and increasing the relevance of each deal.

For LivingSocial the way it is personalizing its offerings is by offering deals that bring people together. One example is a "Salsa and Salsa" deal that combines a salsa dancing class and a salsa making class. “People show up and are able to participate with other users,” said Maas.

Existing sites are also looking at some competition from big tech companies. Facebook is poised to offer daily deals in some markets, and Google, in the wake of its failed bid for Groupon, is reportedly planning to announce its effort in that space soon. Facebook, for its pilot deals, is partnering with established sites including Gilt City, Zozi, KGB Deals, HomeRun.com, and Plum District.