Escrow is a bad idea. Swag is expensive. If I was running a convention that had sponsors, I ain’t putting your logo on anything until you’ve paid for it.
Note, I have helped run a convention. Mostly with logistics and reviewing contracts. So I do have some idea what I’m talking about.
Try being a 19 year old student that goes to a print shop for 200 t shirts and 600 stickers. tell them you'll pay them after the print and be laughed out of the door.
The escrow is not for you and the print shop, the escrow is for the sponsor and you. If this is a typical case where you have to front the money for printing and then get the sponsor money after the fact, then escrow would protect you from companies deciding they would rather not sponsor four days before the event, and well after things have been printed.
If on the other hand companies usually pay up front for a sponsorship, then escrow would not be needed.
When an entity sponsors an event, they begin to redeem the value of that sponsorship immediately in the form of publicity for the sponsorship, website logos, any other relevant copy or press, etc., so at that point since value has already been delivered, "escrow" would not be the correct service.
Because of that, the payment should be direct and in advance. It's just that many community orgs tend not to insist on it because they'd rather bring companies in on good faith (because it's often easier than getting immediate budget approvals).
1. Escrow isn't free in time, attention, or money. (Why does everyone on this site think escrow and lawsuits are free?)
2. Sponsoring an event is effectively marketing. Returns aren't guaranteed in the first place. A $10,000 donation is less than most places spend on google ads for a week.
3. Conventions need the money before they can print anything. No one smart is doing net 30 invoicing for your sub-$1,000 print job.*
* We borrowed a volunteer's $85 laser printer for all of our B&W stuff. Print cost? An OEM toner cartridge and the cheapest box of copy paper Staples had.
Note, I have helped run a convention. Mostly with logistics and reviewing contracts. So I do have some idea what I’m talking about.