Of course everyone says you should never discount your booth rate! This gives the wrong message, sets a bad precedent, etc. But sometimes you need a tactic to get exhibitors to commit early in the show cycle. Here are some thoughts:
Only give something if you get something in return. In exchange for extending this year's rate, you get much needed cash flow plus an enforceable agreement to pay you the full booth fee. But be sure the invoice is worded as follows:
10x10 booth at Widget Expo: $3000 (2003 rate)
Discounted to $2800 (2002 rate) if $700 deposit paid by Sept 30, 2002 (60 days after 2002 show).