Personally I wouldn't use it. While I love the idea of a service which will let me try full songs before I buy them on CD, I wouldn't use it anywhere near enough to justify the $10 a month.
Also, in the time it has taken for the record companies to finally come up with a service like this, most of the music and bands I like have gone indie, and so won't be represented.
Hopefully indie bands will be allowed into the services for a small fee.