Compete has released their May search market share report, which yielded some interesting results:

As you can see, according to Compete data, Yahoo! was the only one of the Big Four to have a month-over-month decrease in search volume. But as the report points out, Google is the only search engine to have a yearly gain.

Some other interesting tidbits and observations from the report:

• Ask.com showed the highest month-over-month increase with 9.1% (could it be “the algorithm“? Maybe Ask 3D? Or the commercials?
• Second on the list of high-steppers was Live.com with a 5.6% increase in month-over-month volume. Maybe Windows Vista / IE7 are starting to pay off. Could Lenovo be sending Live.com more traffic? Of course… it could also be a result of Microsoft’s plan to pay businesses to use Live.com.

It should be interesting to see 1) what some of the other reporting firms come up with for May and 2) if these numbers are just part of the regular cycle of back-and-forthedness that goes along with being a search engine or if they represent trends.