But things get a little more complicated seeing as you don’t tend to spend the full amount of your CPC. That’s because there’s a bidding system that takes place which means you’ll offer spend a lot less. The way this works is simple: if there are two or more adverts both competing for the same space on Bing, then they will enter into a ‘bidding war’.
The ad with the highest CPC will be the one that wins and gets shown but the owner of that ad will only be charged the minimum amount that it needed to win. The easiest way to understand this is to think of it just like eBay – on eBay you can set your maximum bid but you’ll only end up paying $1 more than the next highest bidder.

The same is true with most PPC campaigns and that’s why you end up spending 33.5% less on Bing vs Google – because the lower amount of competition means that your CPC won’t be as likely to get driven up. And of course you also need to consider that your ads will be shown a lot to people who don’t click.