Google is indisputably the most widely used search engine for many years now. This trend will continue well into 2014 and beyond. It is also the reason why many SEM efforts and investments fall squarely on Adwords. When Google was first officially launched in 1998, the average number of search queries per day was 9,800. Last year, we saw an exponential growth of daily search queries made on Google to a whopping 5,922,000,000.
Although, Google is still number one, you might want to start gaining more insight into Bing’s network. Why? In 2013, around 30% of search queries were made via Bing network. Sure it doesn’t sound like a lot but consider this:  Microsoft in putting in considerable efforts to merge internet search with their Windows platform.  90% of computers run on Windows OS.
Bing’s Ad network is a formidable player and something search marketers may want to keep an eye on; even more so if we consider how fast the search landscape changes every year.
Source: statisticbrain.com, forbes.com