I gotta confess I heard about TT pretty late, only a year and half ago, but you have no idea how much I got to enjoy it.
Just to mention one thing, I got completely hooked on Funk - music genre which was completely unknown to me prior to TT
Forget to social aspect, The music discovery alone was simple tremendous for me .. It leaves me very sadden to see it goes.
The reason is quite simple RIAA licensing fees - they just didn't have the business model to be able to afford them ...
I don't think there were many (or any) Audioholics on TT but I tried to promote it here few times and trust me it was worth it.
I probably will be stuck with Spotify for now, which besides ads/subscription completely lacks the TT unique aspect of playing music together.