Yelp traffic could decline for the first time ever after Google changed its search algorithm

Yelp could report a rocky second quarter, with traffic to the site declining for the first time ever, say analysts at B. Riley. 

And it may be all Google's fault. 

Yelp's traffic seems to have slowed following two recent Google search algorithm updates that appear to have affected all local search directories. 

"On a year-over-year basis, June traffic could be down -3%," the analysts write, based on Quantcast data.  "A Y/Y decline in traffic would be a first for Yelp in its history."

Although a traffic slow-down won't immediately affect Yelp's revenue or profits, it's a sign of the increasing competition between the company and Google, which have a troubled history. 

Over the last several years, Yelp raised concerns about Google that ultimately influenced the EU's decision to bring antitrust charges against the search giant.

Yelp says that as Google has bolstered its own local Google+ reviews at the expense of users and other sites, by moving its own search results higher up on the page. Yelp argues that these results are often less relevant, with less reviews per location than other options.

For example, if you search "Mission burrito shop," you'll get a handful of Google Plus listings before getting directed to sites like Yelp and Thrillist. 

A Yelp-sponsored study published at the end of June explicitly called out this practice, stating that "when it comes to local search, Google is presenting its users with a degraded version of its search engine."

Andrew Shotland, at LocalSEOGuide recently posted a series of charts revealing a huge plunge in local guide site traffic following Google's "Doorway" search algorithm update.

The top 30 local directories - excluding Yelp - have had their traffic decline about 35% in the past 28 months, according to the SEO company BrightLocal, which will likely lead to site closures or mergers. 

Although neither BrightLocal nor B. Riley analysts can concretely say Google algorithm updates caused the traffic slow down (it's treated as a correlation, not a definitive cause and effect), this issue is at the heart of the complaint that Google is a monopoly: That it can essentially kill off an entire industry by altering its search algorithms.

Google, meanwhile, always maintains that its updates serve users - its Doorway update sought to eliminate the often spammy practice of building websites with multiple pages with the same text, apart from a few keywords, while its so-called "Phantom" update seemed to impact sites with too many pop-up ads or duplicated content. Whenever Google rolls out broad updates though, there's often collateral damage to sites that aren't actually spammy. 

Business Insider reached out to Google and will update if we hear back. 

Overall, it's been a turbulent month for Yelp.

Several companies were reportedly courting it for an acquisition, and the stock plunged more than 13% when Bloomberg reported last week that Yelp wasn't interested in selling itself after all.