Is Internet Explorer Share Really Plummeting?

This week, TechCrunch trumpets that Internet Exporer is bleeding market share. Since March, IE has lost more than 11 percent of its users. It's an incredibly devastating exodous, in essence giving a vote of no-confidence to Microsoft browsers. Then again, maybe it's all a big misunderstanding.TechCrunch gets its data from StatCounter, which indeed shows that the combined market share of Internet Explorer (versions 6, 7 and 8) has dropped 11.4 percent in the last few months. Yet the mysterious "Other" category has gained almost exactly the same amount in the same time period. TechCrunch attributes that to a combination of Firefox 3.5, Chrome, and Safari. The blog entry also says "It is difficult to make any firm conclusions at this point," but most of the entry is dedicated to drawing some pretty stark conclusions from the data.

These numbers seem very suspicious. Users don't generally change browser versions in huge numbers without making a lot of noise about it, and it's been pretty quiet lately. However, the "Other" category makes a strong move in May. That's too early for Firefox 3.5, and the other possible browsers are all supposedly accounted for with their own lines. So what is this browser that grabbed about 10 percent of the market in only two months? I don't think there is one. I will note, however, that IE8 was released in late March and began to be pushed out via Automatic Updates in late April.

Is it possible that the StatsCounter data is misreporting IE8 when it is running in IE7-compatible mode? Another stats company, Hitslink says that this causes IE8 to misreport itself about 10 percent of the time, which is -- surprise! -- about the same boost the "Other" dotted line has gotten since IE8 began to be pushed out via Automatic Updates. You'd think that IE8 reporting itself as IE7 would simply prop up the existing IE7 number, but maybe not.

Getting a handle on browser market share is tough; it's not an exact science. Any time the data shows something that seems hard to believe, it's a good idea to not jump to extreme conclusions. When other browser-share measurements finally do become available, we may find that there haven't been any massive moves in browser market share over the past few months. If you just spot Microsoft the 10 percent that they are probably due, IE's overall share is sitting just about where it was a year ago.