Microsoft seems to be getting pretty desperate, they will actually pay you to use Bing! Microsoft have started Bing Rewards, which lets you sign up to earn money for using their search engine.
The idea about search engines is to provide a service people that allows them to find things on the internet and have advertisers pay to advertise to those users. As Bing is underperforming, Microsoft seem to now need to split the advert revenue with users to get people to use the service over Google.
To me, this method doesn’t seem sustainable. Imagine if this happened with other products, such as your TV? Imagine if TV was so bad that people started doing other things, so TV companies would end up paying people to watch TV? All this is funded by advertisers, of course, which really takes a punch out of the power of advertising.