According to a recent study by Brightlocal, Google is acquiring new reviews much faster than Yelp, Tripadvisor, Facebook and Foursquare. And as of July 2017, businesses were receiving more than double the amount of new Google reviews they were just a year before.

Since releasing Google Maps in 2005, the search engine behemoth has made inroads into the local review space. But this data shows more than progress. Google seems to have hit an inflection point and is now blowing away the competition. Could this be a sign that Google will make other local review sites extinct?

The answer depends on the unique drivers of its growth and the sustainability of those drivers. The rise of Google reviews seems linked to 3 massive distribution channels: Google’s Android phones, Google Maps and Google Search. According to the Pew Research Center, 77% of all Americans now own a smartphone. Google has been able to tap into mobile users with both their Android phones and dominant Google Maps. So anytime a mobile user searches for or needs directions to a local business, they are looking at business profiles and reviews courtesy of the Google Maps app.

Furthermore, Google Maps has made a simple but important product enhancement: it can identify users’ recently searched for and visited locales and automatically trigger a prompt asking users to leave a review.

The prompt makes writing a review easy for consumers, and it allows Google to get a review from someone who might never have bothered to leave one. This is a big difference from other review sites, which have been critiqued for only capturing the very positive or very negative experiences because of how much effort it takes someone to write a review: open and/or install a separate review site app, find the business, and write a review with enough detail that it will not be filtered. Google, on the other hand, can capture a broader range of reviewers – less motivated but perhaps more reflective of the average consumer’s experience.

This last point touches on an additional benefit for Google: the prompt lets Google qualify authentic reviewers more easily than other review platforms. Due to businesses trying to game their ratings, other review sites expend significant effort evaluating the legitimacy of reviews by analyzing the user’s behavior and content of the review comments. Some of the filtering can be automated through AI and natural language processing technology. But since the state of the art is not where it needs to be, many review sites err on the side of caution and over-filter reviews, screening genuine ones alongside the fakes. (Yelp, for example, screens 25% of their reviews). Google, however, can qualify reviewers based on their search intent and GPS coordinates.

Finally, Google has their ubiquitous search engine, which in recent years has prioritized Google Maps and placed it at or near the top of their search results. This means links to other review sites end up being pushed beneath Google Maps, further down the page, where they inevitably receive less traffic. When it comes to search, these sites are at the mercy of Google.

But incumbents do have their advantages which may not be easy to overcome. User-generated content – comments and photos – tend to be much richer on other platforms and thus more helpful to other consumers. At Reputology, an analysis on character length in the body of the review comment found that Google reviews are about 150 characters in length – the size of a Tweet. In comparison, Facebook averages closer to 300 characters and TripAdvisor comes in at 450. (That’s roughly double and triple the number of characters, respectively). In other words, visitors of those other websites get more information about what reviewers liked and disliked.

Another impediment to Google’s dominance may be their reliance on the Local Guides program, which has also helped drive new reviews. The Local Guides program rewards members with perks in exchange for creating/editing content for businesses on Google Maps, and this includes leaving reviews. Those incentives may make those users feel more warm and fuzzy when writing a review, which would create a bias that an un-incentivized reviewer would not have. A lack in authenticity in reviews could compromise consumer trust in Google reviews.

Also, other review sites can be much more focused on being review sites, whereas Google has other initiatives: self-driving cars, virtual reality, drones, etc. Google may not be as successful at providing consumers with high quality reviews simply because they have have other priorities.

Even within the review site industry, vertical specific sites for autodealers like Cars.com and Edmunds.com or healthcare like Vitals.com and Healthgrades.com exist because they can offer many more details and features to visitors than a general local search directory.

Moreover, some industries have evolved alongside Google Maps rather than become obsolete, like travel and hospitality. When you search for hotels on Google Maps, reviews sourced from Orbtiz and Expedia may populate the results.

So even if Google gains poll position, it could partner with other players. But if Google continues leveraging its large distribution channels & counters the advantages of its competitors, the search engine giant may just take all the traffic for itself.