Well its completely music orientated for one. Also the group/recommendation system makes it an awful lot easier to push your work. The gig announcement system also is very good. Basically, last.fm makes recommendations based on listeners habits/tastes. The groups are also a good way of channeling hits, plus personally I've found it to be invaluable for finding music thats new to my ears. Which, to tell the truth, is what I focus on a lot more on the net in general, than promoting my own stuff.

Er.. Its easier to promote if you can actually be bothered, I hardly have been tbh as I'm busy doing unmusic related things until something being planned comes together.

Myspace is changing a lot, so i dunno about if its worth staying on there. I've not deleted my old page, but I only go there to pick up the occasional email now.

Edit : Impressively (to me) my rec radio station played 'global electronic network' - 'Times Square III' to me during my first week using the scrobbler. Thats one of my all time favourite tracks, pretty obscure too tbh. It used to be a staple of my old DJ sets.