Several analysts issued first impressions of online deals site Groupon Inc. on Wednesday as they initiated coverage, mostly with lukewarm ratings and a "prove it" stance.

Citi Investment Research analyst Mark Mahaney gave the Chicago-based company a "Neutral" rating and set a price of $24 for its shares — $4 above the stock's initial offering price. Mahaney said Groupon has been "extremely impressive" so far but must succeed in new segments to make substantial progress, and that could take "significant time to prove out."

Citigroup was one of Groupon's underwriters when the company went public early last month.

Morgan Stanley, a primary underwriter for Groupon, started coverage with an "Equal-weight" rating and a price tag of $27. He said the company is seeing strong growth, and it's expanding its offerings to both consumers and businesses. But he cautioned that Groupon's bread and butter — local e-commerce — is a difficult business to forecast.

"Groupon (and competitors) must consistently provide high-quality deals, which may be increasingly difficult as merchants gain digital marketing sophistication," analyst Scott Devitt wrote in a note to investors.

Janney analyst Shawn Milne also started Groupon with a "Neutral" rating. He called Groupon a "clear leader" in the fast-growing daily deals market but also said that the company will need to broaden its business to succeed.

Goldman Sachs, another primary underwriter, stood out with a "Buy" rating and $29 target price on the company.

"We view Groupon as the key to unlocking the massive local advertising market with which the Internet has long struggled," analyst Heath Terry, wrote in a note to investors.

Groupon declined to comment on the analyst reports.

The shares fell 77 cents, or 3.3 percent, to close Wednesday at $22.55.

Since opening at $20 on Nov. 4, the stock has traded as low as $14.85 and high as $31.14.