Google+

I've been using Google+ now for a couple of days, and I have to admit I like it.
Currently it suffers from being almost 100% self-referential... everyone on G+ only talks about G+.
Apart from that it reminds me a lot of friendfeed. (Odd, since FF was bought by Facebook - of all).

I wonder why they did not implement hash-tags (like twitter). They'd link individual posts to topics, so they provide additional (and in many cases) valuable information - or meta information.

G+'s most important task is to get additional signals to improve Google search/index, so hash-tags should serve well there. Wouldn't they?

Or does Google consider hash-tags as "messing with the algorithm" because they are being entered by humans... and not derived from their algorithms?