With Apple's Mac home market share tripling in the past five years, Microsoft has fought back with its own advertising campaigns attacking Apple for the first time, a move one analyst sees as a mistake.

In Sunday's New York Times, Devin Leonard took a look at the advertising battle between Apple's "Get a Mac" campaign and Microsoft's "Laptop Hunters" and "I'm a PC" TV spots. He said that the ad war between the two companies is "destined to go down in history," with the likes of the Pepsi-Coca Cola rivalry of the '80s and '90s. But in a new note to investors, Charlie Wolf of Needham & Company said the Mac's recent market share gains are a result of much more than advertising. In addition, he said the Windows maker would be better suited using its money to combat overseas piracy in emerging countries.

"One has to admit that Apple’s 'Get a Mac' campaign was humorous if nothing else," Wolf said. "But why Microsoft responded with an ad campaign of its own is a mystery. The company erroneously attributed the Mac’s share gains to the 'Get a Mac' campaign... However, the damage done to Windows' worldwide market share was miniscule.