Bounce rate is a very important figure in helping you decide what your website visitors like and dislike.
When you know this information you can start to make decisions on what to change to improve the user experience and ultimately your leads & sales.
The typical bounce rate of website is 40% so if you have anything larger than that it is time to take a serious look at the relevant pages.
When you see a higher bounce rate from mobile visitors to your desktop site it is very likely to mean you need to have at the very least, a responsive website (Where all your desktop content can be viewed on a smartphone)
Alternatively you most certainly need customised mobile pages (Smaller amount of content than your desktop) which are created exclusively to meet the mobile searchers expectations, leading to even more new leads & sales.