Online review website Yelp(YELP) - Get Report could find itself in the cross-hairs of an activist in the near future, after losing almost a quarter of its value Wednesday in the wake of slower revenue guidance for the year.

The company watched its shares plummet about 20% Wednesday to $28.40 per share, its lowest level since the June of 2016.

The decline in its stock price, coupled with an advertiser revolt and increased competition from Alphabet(GOOGL) - Get Report and Facebook(FB) - Get Report in local advertising, part of Yelp's bread and butter, raises questions about if the company can go it alone - concerns that have long dogged the stock - and could open up the door for activist investors to push for a sale.

"There are now substantial questions about Yelp's salesforce execution and its current value proposition for advertisers. And fundamentals are deteriorating," Mark Mahaney, an analyst at RBC Capital Markets, wrote in a note Tuesday evening. "This won't be a quick fix."

Yelp's latest management missteps also come as competition is intensifying and activist investor Corvex Management is pressuring Pandora Media (P) --another struggling high-profile Internet company-- to find a buyer. Consolidation in the sector is also heating up, with Angie's List's acquisition in May by IAC/InterActiveCorp. Yelp's board may have less choice in the matter this time around if an activist threat were to mount given the botched execution and intensifying competition.

Yelp, which did not respond to a request for comment, already counts some activists among its shareholder base. David Einhorn's Greenlight Capital had taken a stake in the company in 2016, noting then that the company could be acquired if the board wanted a deal according to a quarterly letter to investors obtained by Bloomberg. Portrero Capital, which launched a campaign against Datawatch Corp. (DWCH) in 2016, is also a shareholder.

A change in how Yelp charges advertisers -- from "cost per a served" (CPM) to "cost per click" (CPC) -- triggered the downbeat revenue forecasts for the year, according to analysts. 

"Management said that 1Q churn was elevated due to the anniversary-ing of the transition from CPM to CPC pricing last year," analysts at Cowen and Co. wrote in a research note Wednesday. "the 1Q elevated customer churn means that the customer base mgmt. expected for the entire year fell short and will cascade through the balance of the year. As such, management was forced to lower revenue guidance for the year."

For the quarter, Yelp's revenue of $197.3 million fell below Wall Street's projections $198.3 million. And the San Francisco-based company also lowered its full-year sales forecast to be in the range of $850 million to $865 million, down from its prior estimated range of $880 million to $900 million. Wall Street, meanwhile, was looking for revenue of $888.7 million for the year.

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Yelp's latest struggles come as more users turn to social media sites like Facebook for local recommendations, and search engines like Alphabet's Google report strong growth in local shopping searches and local inventory listings.

Whether activist investors will have the patience to wait for a Yelp turnaround is another question. Pandora recently took steps to shake up its board and take an investment from a private equity firm to fend off an activist investor Corvex Management. Corvex Management CEO Keith Meister has long advocated that while he admired the product, he did not see Pandora's viability as an independent company.

While investors have long viewed an acquisition as an appealing outcome for Yelp, the latest results may limit Yelp's say in the matter. And while Yahoo! Inc. (YHOO) , which is in the process of being acquired by Verizon's (VZ) AOL unit, had previously been thought of as a likely suitor, an increasingly acquisitive IAC may be a more likely option this time around.

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