Determining how popular a WNBA team is is almost a fool's game. There are several ways you could judge popularity, and none of them are very satisfactory:
* For some franchises, attendance numbers have little correlation to the number of people actually showing up.
* Doing a count of Google hits weights numbers in favor of the franchises that have been around the longest.
* So little WNBA franchise-specific merchandise is sold that the numbers could wildly distort fan interest.
In my opinion, the biggest problem with determining franchise popularity is the "sideways hockey stick" nature of fandom itself. The fans of any WNBA franchise should be dominated by "casual fans" - those fans who might come once or twice a year to for a summer family outing, but who don't really pay much attention to the league or its personalities.
One way which might be useful is to look at hits on the Wikipedia article under the franchise name. These hits capture the interest of the casual web-surfer who might need to know to which sport the "Chicago Sky" franchise belongs but needs no more information than that. The hits also:
a) count the interest of hardcore fans, who might visit an article several times, and
b) also count how much interest there is in keeping an up-to-date article, as every visit by an editor will be counted as a hit.
In this fashion, a hard-core fan's interest is weighted heavier than a casual fan's. An argument could be made that this weighting is very appropriate, and I'm sure that hard-core fans would make it.
I decided to count the number of Wikipedia hits for every franchise for the year 2012, and I hope that this reflects accurately the popularity of various WNBA franchises.
Granted, this isn't a perfect method of gauging franchise interest. One could argue that Wikipedia hits might measure notoriety as well as any significant interest. For example, the Indiana Fever has a massive peak of interest for the month of October 2012, where the number of hits for October are almost 5x that of the closest month, September. This number of visits was undoubtedly caused by Indiana's WNBA championship in October 2012. Even so, an argument could be made that notoriety equals popularity, at some level. Undoubtedly, a lot of people who had never heard of the Indiana Fever know who they are now.
Another argument might be that a Wikipedia article might not be the primary source of information for a team. It's a good point to make, but sadly there is no way to judge the rightness or wrongness of the argument.
The total list for 2012 follows
2012 WNBA Team Ranking by Wikipedia Hits
The next question is, "do the results pass the smell test?" For the top four teams, you could make a good argument that this list accurately reflects overall popularity. Tulsa seems a little high, but Tulsa's month to month numbers are fairly even - there's no massive peak in interst like that of the Fever. Maybe WNBA fans like the Shock a lot more than people think they do.
In general, Western Conference franchises are more popular than Eastern Conference franchises. This meshes with my experience. Seeing Washington near the bottom seems to make sense, but seeing San Antonio at the bottom is a head-scratcher.
Before you think these numbers are impressive, let's look at the year numbers for the various Atlanta teams.
2012 Atlanta Sports Team Ranking by Wikipedia Hits
|Georgia Tech FB||100114|
This doesn't even count the Georgia (or Georgia Tech) men's basketball, or any of the other various Atlanta sports. The Dream have a long way to go, not just in the WNBA but in their own city. I suspect that even the Los Angeles Sparks would have to come to the same conclusion.