Years ago, my company decided to attend a show (rather late in the game) that got far more attention than even the promoters expected. The demand outpaced the supply so they set up large tents for overflow and unfortunately, we were in an overflow tent.
One of the more experienced sales types saw the situation and immediately departed stating he would be back shortly with an answer to our dilemma. He reappeared in about 2 hours pulling a portable popcorn machine! While I had my doubts, I was up for anything as traffic was dismal. Within minutes he had the smell of popcorn wafting thru the entire area and into the main arena. Traffic steadily picked up and never slacked up for the entire three days. Great smelling coffee works in the morning and the news of apple martinis works in late afternoon, but the aroma of popcorn makes its own introduction and will draw a crowd in most circumstances.
If you opt for this strategy, remember the vacuum!