I wouldn't be so excited about this spike. I feel it may have been created by a botnet auto creating a bunch of accounts on 18th and 19th. It doesn't look natural.
edit: You can also see the "active user ratio" dropping significantly in the same timeframe.

What I hate about that is that this hurts anyone looking for information just as much or more than in hurts reddit itself. I've stopped using reddit's feed and general participation, but there's still alot of valuable information on there that helps me and others in their daily life. Destroying the content feels like burning the books in a library because the library introduced an unpopular policy.