An employee works in the Yelp Inc. offices in Chicago, Illinois, March 5, 2015. REUTERS/Jim Young Yelp shares tanked 28% on Wednesday after the company slashed its outlook for full-year earnings.

In second-quarter results released Tuesday, Yelp said it expected net revenues to be between $544 million and $550 million, which would be 54% higher year-over-year. Adjusted earnings are expected to be between $72 million and $78 million.

The business ratings and reviews platform lowered its outlook "based on slower sales headcount growth and the elimination of its brand advertising product."

Deutsche Bank analysts slashed their price target on the stock to $26 from $33, with a "hold" rating, in a note Wednesday. They mentioned that there was growing competition for Yelp's sales force and that the company had slowed down hiring.

As for its most recent performance, the company posted revenues of $133.9 million, ahead of the consensus estimate for $133.5 million according to Bloomberg. Yelp posted a loss of 2 cents, worse than the estimate for 1 cent. Adjusted Q2 earnings per share came in at $0.12, versus the forecast for $0.16.

Mobile unique visitors to the site exceeded desktop uniques for the first time, up 22% year-over-year and averaging 83 million per month, Yelp said.

"Consumers are increasingly turning to apps when using their mobile phones, and we are excited about the growth we've seen in app usage, which accelerated to 51% year-over-year," CEO Jeremy Stoppelman said in the statement.

Yelp announced during the conference call that chairman Max Levchin would be stepping down to go after other interests.

Earlier this month, Bloomberg reported that Yelp was not looking to sell itself after being approached by several companies.

Yelp shares are down 54% year-to-date and 64% over the past 12 months.

Here's a 12-month look at the stock: