If you have an option to choose between a free, ad-supported mobile app or pony up a dollar or whatever the apps costs, you might be better off buying the app.
New research from the University of Southern California, Rochester Institute of Technology, and Queen's University found that compared to apps without ads, apps with ads are a big drain on your battery, take up more processing time, and also use much more data.
We've noted a while back that most of the energy used up goes towards powering the ads in these free apps, but now we have some real world figures on what this means. These apps can lower your phone's battery life by 0.4 to 0.8 hours, depending on how you use them. The bigger memory usage also means your phone will run slower.
If you don't have an unlimited data plan, that higher network data use also can cost you.
As usual, be wary of things that are free, because they often come with a cost.