1 - paste a link here! There used to be a links section on PCA but it is now gone as far as I can see (maybe because no one looked at it...).
2 - advertise in the relevant magazines if that is in your budget - even a small classified ad should help.
3 - does google list your site - maybe check out the cost of advertising with them.
4 - have you looked at price check sites like kelkoo.co.uk, pcindex and so on?
I know nothing at all about e-commerce so the above is only some basic musing.