How many 10 x 10 booth spaces will I need?
A good rule of thumb is 3 rolling racks (or 2-3 tables) fill one 10 x10 booth space. Most vendors find that they need at least two booth spaces for the best presence & visibility.
Remember, 2 booths is 10 x 20, not 20 x 20 (that is 4 booths).