Our local dealer used to have free weekly demos of all his boats at our local lake. After a period of a couple years though it got very obvious that there were quite a few locals that were abusing the policy using the boats as a free recreation with no intent of ever buying a boat. That policy is now suspended, now if you want to demo a boat he’ll take you to the lake with the boat you want to try, still free, but less abuse of the policy.
I’ve seen two good models
My local dealers know me, and I have bought boats from both of them. One allows demos for free, you take the boat away and bring it back. Fantastic service, which I don’t abuse. The other has free demo nights. I think the demo nights are great for both serious buyers (who can request a specific boat) and those who might be thinking of kayaking, but haven’t even tried it. I tried my first sea kayak here, loved it, and eventually bought one, years later. The demo nights are a great way for the dealer to meet many prospective customers.