Bing, Microsoft’s search engine, has had a good first year. Comscore reckon it’s taken 12.7% of the US core search market since its inception. That’s getting near Yahoo’s 18.9%, (NB: most of Yahoo’s search is now powered by Bing, although Yahoo Japan have, in a surprising move, gone for Google ), though still pretty far away from Google’s massive share. Other reports from other net-research bodies have differing figures, but the consensus puts Bing a respectable third place behind Google and Yahoo.

So, what happens next? What scope is there for expansion in Bing’s market share? Microsoft appear to be taking opportunities where they’re available – helped of course by a healthy amount of investment – and have been targeting mobile web users. With 23 million mobile web users accessing Bing (and 4.3 million downloads of Bing’s iPhone app) it seems to be paying off.

According to Erik Jorgensen, senior vice-president for mobile at Microsoft : “People drive themselves crazy trying to type on these mobile devices so the more we can understand what they are trying to do and provide an easier way to get to it through visual, voice and touch is a key insight into how mobile search is going to evolve.”

How much bigger can Bing grow before they hit the brick wall that is Google’s market dominance? Or could Bing be the legendary Google-killer? Give us your thoughts in the comments.