You get a (3D) printer!

We can make back some money if we give printing paper some adspace, small watermarks off to one side. 

We could even couple it with software to make the ads take up more space, and so make it even cheaper. Each sheet could have ads already printed in weird patterns that special software is built to keep a track of and print around, so that eventually most printed documents look like those cluttered news websites, where you can't tell the content from the ads. Since this will force users to read the ads before filtering them out, prices will drop down further. 

We could make it so that you can only use this proprietary software, allowing even more ads when using the software as well. By this point everyone can get one free printer per day. 

Bonus: 3D printers. Imagine 3D printers selling for dirt cheap, but every print you do also prints a fun moving contraption that's also an advertisement. The 3D analogue for pictures of beautiful women to grab attention is left as an exercise.