[wwsculley]

I think the question you need to ask yourself before - How can I increase the net traffic to my site? - is: Why do I want to increase traffic?

Building out a customer base for the sake of increasing numbers leaves too many open questions. Building one for a specific purpose, however, (e.g. increase ad revenue, subscriptions, user-relationships) can help shape the direction of the site's development. It is much easier to increase the volume and stickiness of your audience if you can give them a purpose to look forward to.

That said, the nature of your product should dictate this direction. If you are selling a specific product, consider what modifications and accessories will complement the original product, and to what extent that will draw back loyal users.

Why should I buy an iPod? Because I am confident that I will enjoy engaging with it, look forward to the next model, and that I will be able to relate with my friends about it (consequently encouraging friends without one to get one). Engagement is more important than ownership.

In terms of social music networking, consider what ways that you can allow your users to engage with one another through the product, and to give them some agency over the process.