Our favourite digital music service, Spotify, is three years old today. That seems like a lot, considering we’ve only been able to use it in the UK since October, but in that short time it’s already completely changed the way I listen to music on my PC, and made me listen to a much wider range of bands too.

To celebrate the anniversary, as well as the 40th birthday of founder Martin Lorentzon, the company has put up a blog post that talks (in somewhat vague terms) about the future direction and plans for the company.

There’s a lot of hints in the blog post about mobile devices – something that the company hasn’t been keeping very secret. Intriguingly, though, the company also mentions set-top boxes, IM, and social networks as future directions for expansion.

Spotify mentions, too, the possibilities of enhanced social features and pre-release content for premium users – something that could drive greater takeup of the subscription service. That gets interesting in the comments section – with several people saying that if the fee was halved, then they’d pay it. I wonder if they’d get twice the takeup if they chopped the price in half.

The most exciting bit, though? The closing sentence of the post – “We plan to have more detailed information for you in the next few weeks, stay tuned”. If I were a betting man, I’d put money on that being the iPhone application that we revealed in February, a leaked video demo of which is posted below.

Spotify Blog