Ads only one of the reasons. Reddit also updated Reddit Coins [0] with their new design. With this new "in-app" economy, you can use real money to buy reddit coins and give an award to post. Another revenue stream for reddit.
They give me Reddit coins because I donate every month. I don’t use their app and have no trouble giving out coins for posts that I like. Sort of fun, BTW.
Now, I really wish Twitter would let me pay a monthly fee for no advertisements.
