Sure Google has the lion's share of the search and ad markets but keyword prices are decided by an ongoing electronic auction and Bing's cost less.
According to David Pann, the General Manager for the Search Network at Microsoft.
"Yahoo! Bing Network reaches 151 million searchers in the U.S. who are likely to spend 24% more than the average searcher, and likely to spend 5% more than Google searchers in the U.S."Depending on where you live and the business you're in, you may need Google to generate your desired amount of traffic. But if yours is a small business whose budget can't buy many of the clicks available on Google anyway, it would make sense to run a Bing Ads campaign. For the same money, you could generate a lot more clicks.
It depends on the size of your business, your ad budget and your traffic requirements but for a lot of small businesses, skipping Google and running a Bing Ad campaign could make a lot of sense.