As Google learned with glass and Twitter still needs to learn:
If you don't know what your product is for, your customer is unlikely to figure it out for you.
If you don't know what your product is for, your customer is unlikely to figure it out for you.
The decline started when they started building what the VCs thought would be a winning lottery ticket: that was when they started closing the service and everything became focused the pitch to advertisers without enough balance on what their users might want.