So you're hosting a conference and you decide to charge for exhibition attendance, what's your strategy? Often, a baseline charge is a good way to make an event more exclusive, providing the exhibitors with a filter that reduces the number of people who attend simply to sell the exhibitors something.
Put differently, if you're hosting an exhibition, you're exhibitors would probably rank conference attendees as their best prospects, people who use the products or are in the industry as second best, and the least desirable being the vendors and businesses that attend simply to sell products or services to the exhibitors -- exhibitors, publications, consultants, shipping companies, suppliers. We've even had people come in off the street collecting bags of booth give-away stuff -- on occasion.
An on-site charge can go a long way to prevent this kind of traffic.
However, I'm trying to imagine the "bad" traffic in that mix trying to sell to companies exhibiting at a search marketing conference. Now weigh that against the potential "walk-in" customers to an exhibition that might actually benefit from the products or services that a company exhibiting there would display. If I were an exhibiting company, I would be pissed. Or rather, I wouldn't be a repeat exhibitor.
This is to you, sponsoring companies of the SMX West Expo -- I won't be visiting the expo because they decided to charge for expo admission. I don't know anything more about you or your business. Google, Yahoo, I didn't get to speak with your team there. AimClear, Alight Analytics, Marin Software, SEORadar, Moz, Yext -- I missed seeing your booth. If you were trying to reach me, your marketing dollars were wasted. Were I in your shoes, I'd express some concerns.