Found these two articles about 800 numbers through Twitter and thought I`d pass `em on:
Get more from your 1 800 number.
Use toll free number to track marketing.
And on that topic, has anyone tried using different 800 numbers for different departments? There`s not that many of us, but is it better to have one for ordering and one for support, or is it just fine to use one number and then route from there?