Is the bloom off the user review site rose?

Last March, I wrote the post Has TripAdvisor overtaken Yelp for winery visitors, suggesting that of the two major user-review Web sites, TripAdvisor seemed to be replacing Yelp as the preferred forum for people writing user reviews of Paso Robles wineries.  The graphic I included in that post showed a pretty dramatic shift over time:

The graph also shows a steady increase in the number of user reviews posted for Tablas Creek on the two sites, from 10 in 2008 to 15 in 2009 to 22 in 2010 and 42 in 2011.  With the first quarter of 2012 showing as our busiest quarter yet for user reviews (18) I fully expected to see continued growth.  But something happened around the middle of last year, and while our annual total (63) was still our highest ever, the quarterly total peaked in the second quarter at 25, then declined to 13 in the third quarter and just 7 in the fourth quarter.  I have gone from checking the sites daily for new reviews to now checking only every week or so, and getting used to seeing the same months-old reviews I saw last time.  The curve looks a little different now. To smooth out some of the noise, I've added a rolling average, which averages each quarter with the quarters before and after:

It's worth noting that my conclusion that TripAdvisor -- which to most wineries at the time was much less salient than Yelp -- was a player to watch turned out to be true. TripAdvisor tallied nearly three times the number of reviews of Tablas Creek as did Yelp in 2012.  But by sometime around mid-fall the flood of user reviews had turned to a trickle.

I was curious to know whether what we were seeing, both in the drop in user reviews at the end of 2012 and the dramatic shift toward TripAdvisor and away from Yelp, was standard for our area.  So, I picked three other popular, well-established Paso Robles wineries (Justin, Adelaida and Eberle) and took a look at what they'd seen.  I found that the shift toward TripAdvisor and away from Yelp is real, and dramatic.  In 2011, the four wineries (including us) showed 133 reviews from Yelp and 44 from TripAdvisor.  In 2012, Yelp reviews declined 34% to 88, while TripAdvisor reviews grew 390% to 216.

And I found that the dip in reviews I'd noticed in the second half of last year was echoed by our neighbors, though we saw a larger decline than most.  Here are the four wineries' results for 2011 and 2012, using a stacked area graph that allows you to get a good sense of the aggregate:

My first thought was that this could be explained by the number of customers visiting Paso Robles.  After all, the summer season is typically the busiest one in Paso Robles, and the winter the quietest.  But when I looked deeper, I found that at least at Tablas Creek our tasting room traffic doesn't vary that much by quarter.  Our smallest quarter last year was indeed the fourth quarter, but at 6880 visitors it was only 12% less busy than our busiest (the third quarter, at 7815).  I don't have any reason to think that our traffic trend differs significantly from the other wineries in the area, so I tried dividing the total number of reviews for each quarter by that quarter's traffic.  The results show that per Tablas Creek customer, we are seeing a decline in user reviews submitted for the four wineries:

There are few possible ways of explaining away the development, none of which I find particularly convincing.

• Perhaps there is a different type of customer who visits in the summer months, a younger, more tech-savvy customer, who is more likely to post a review on Yelp or TripAdvisor.  Maybe, but If you look at the results for 2011, the two summer quarters showed the lowest percentage of reviews per tasting room visitor. Why would this reverse itself in 2012?
• Perhaps there is something about the four wineries that I chose that makes us all subject to some trend that is out of step with what's really happening.  This is possible, but seems far-fetched.  Other than that we're all in Paso Robles and all of roughly similar scales, we represent wineries that are in different parts of the AVA. Could, say, newer... or smaller... or larger wineries have been getting more reviews at the end of last year even though our traffic stayed steady? I just don't see how. The implication would be that there is a specific sort of person who writes these reviews and that sort of person hasn't been visiting Tablas Creek, Justin, Adelaida or Eberle as much in the last six months even though our overall traffic numbers are steady. Maybe they're now boycotting Paso Robles in favor of other wine regions? I have trouble believing such an explanation.
• Perhaps there are as many user reviews being written, but there is a new competitor in the field that is siphoning off reviews from both Yelp and TripAdvisor.  The obvious option is Google, whose Google+ allows users to write reviews. But the five Google+ reviews of Tablas Creek include only two written in the last year. The other competitor mentioned sometimes is CitySearch, which has only three reviews of Tablas Creek, just one written since 2008.  So, if they're moving away from TripAdvisor and Yelp, where are they going?

In the absence of another plausible explanation, I'm left to think that there has been some sort of shift against both Yelp and TripAdvisor among their users in the last six months.  Unless this is a statistical hiccup that will correct itself over the coming months (possible if unlikely) the possible conclusions are that we're seeing the bursting of a bubble that will eventually lead to a steady but lower-level number of new user reviews, or that this is the beginning of a long-term trend that will result in the category's gradual obsolescence.  I would tend to suspect the first explanation: that like with many new technologies, lots of people jump onto the bandwagon when they see their peers doing the same, but many find that it's just not for them. And it is work, writing these reviews, uncompensated work at that.  It's easy to imagine a reviewer getting fatigued with what's involved.

From a practical standpoint, even if it is true that user reviews are declining, the sites are still important for wineries to monitor. Both sites (particularly Yelp) are search engine goliaths, and there is well-documented evidence that even a single negative review can make a significant difference to a restaurant. A decline in the authorship of reviews doesn't imply a decline in readership, and in fact good reviews are more important now than ever, as there are fewer reviews being written and a negative review is proportionally more influential with a lower volume of other reviews in which it can get lost.

Still, I was interested to see that what seemed like an endless escalation of user reviews has not just slowed, but reversed itself. We'll see, over coming months, what this means.