If you haven't noticed, consumers don't care for DRM. We like to buy books and music once and then put them on any of the devices we own that we want to. DRM will often keep you from installing your legally purchased content on all of your devices. A new report has been published looking at indie books on Amazon comparing the sales success of DRM laden titles to those lacking DRM.
The report has found that independent books being sold on Amazon without DRM are selling at a 2:1 rate compared to those with DRM. Digital books from the big five publishers almost all use DRM. When it comes to indie books, only about 50% of the titles are published with DRM.
At the end of the day, the report found that independent books selling without DRM installed significantly out-earned titles that had DRM. The only price point where DRM titles from independent authors outsold titles without DRM was at $6.99, where two books from a single author are outliers.