A Reverse Expo is an industry exposition or conference where the "buyers" staff event booths and the "vendors" circulate and meet with buyers. This concept appears to be a growing trend in the exposition space as "buyers" seek to limit the length of time spent at an exposition and "vendors" seek to introduce their services/products in the most effective way.
Similar reverse expositions have been noted in the supply chain, healthcare, and food production industries.
References
Reverse Expo Wikipedia(Text) CC BY-SA