My idea for the first design was
that if you were buying things the orange would be the prominent
colour on the web pages you viewed, if
you were selling things blue would be the prominent colour and the
logo would rotate 180 degrees. The logo could be animated to
rotate when you clicked on the 'sell item' button.
Customer asked for "something like a
solicitor's logo", so after a number of designs based around
wood, metal, and engraved plaques, I came up with the other designs.