If you are planning to attend a fair in a few days/weeks, you should read this article: What to ask for at a tradeshow (and afterwards too).
David Dayton came up with a great list of questions that importers can ask the exhibitors they meet on sourcing fairs:
Where is the facility and can you go to visit (this week while you’re in the country)?
Will the person that you’re speaking with at the show be in the factory when you go to visit (so you don’t have to repeat everything you’ve gone through today)?
Do they have business documents that they’ll let you see?
Will they let you talk with engineers and other managers?
Will they allow 3PQ [third-party QC firms]?
Can they give you referrals?
Will they sign (and keep) NDA’s and other agreements?
Can you meet and even QC sub-suppliers?
Do they have the correct export documentation?
Have they exported to your country/region on the world before?
How much of their production do they outsource?
How do they deal with non-conforming product?
I would only add “are they familiar with your country’s safety standards?” and “does your company belong to a mainland Chinese person?”. This list is really good.
He also came up with a list of questions that will allow you to evaluate whether exhibitors are a good fit for your needs:
What is there average order qtty? Is your order similar?
What is their average order time? Is your lead time sufficient?
Have they done similar projects (similar levels of customization, similar components)?
Can you communicate with them effectively and do you feel comfortable working with them?
I couldn’t agree more… Maybe you can also ask about the seasonality of their business, about what distinguishes them from their competition (generally nothing), and whether some top managers speak English.