The mobile operating system designed to save Microsoft’s mobile business is struggling.  A month and a half after its launch, Windows Phone 7 is outnumbered over 100 to 1 by both Android and iPhone, based on traffic through the Chitika ad network (http://chitika.com/).

Over the past three weeks, for every one Windows Phone 7 impression Chitika saw, there were 110 Android impressions and 172 iPhone impressions.  That number is remaining relatively stable, with very little significant market share growth in WP7, according to Chitika.

“Given that both Android and iPhone see their biggest spikes in usage during weekends, Microsoft may do well to position Windows Phone 7 as a BlackBerry nemesis rather than an iPhone/Android killer – the corporate worker’s smartphone of 2011,” says Daniel Ruby, research director, Online Insights, Chitika.