First off, we should not be discussing sales related things with a registered user. Since this is a general topic of some worth to the group here, I'll let it sit for now. BUT, please no discussion of selling....just about freebies and testing.
As a person with nearly half a century of retail experience, I can tell you a few things;
1) NEVER call anything a freebie. The name in itself says the item is worthless. Call it a sample, call it a test knife, call it a proto-type...buy not a freebie.
2) Making and distributing a limited number of filed test proto-types ( sounds a lot better, doesn't it) is a good thing. Make the number reasonably small, as you still want a market when the field testing is done. Choose the recipients wisely. It should be people who regularly use the knife type you are testing. Giving a drop point hunter to an office worker, or a chefs blade to a mechanic is not going to get any usefull feedback. Make up a sheet with critiques on the knife for the recipients, otherwise, they will just say, :"It was OK.". Tell them to be brutally honest. The critique should cover looks, feel, balance, hand friendliness, cutting ability, edge retention, suitability for the design task, and other comments. it should have a suggestion space at the bottom. It should NOT have a place for their name.
Choosing recipients who do not personally know you directly is a really good method. many folks do that through a pass-around on the forums. You can make a few knives and send them out for testing and use by different groups, and when done get the knives back. This way you can observe how the knives held up, and haven't lost the knives. A pass around among knife people will get you the most honest and useful suggestions and reviews.
3) Don't do this if you have a thin skin. Anyone who wants to help you will tell you the truth. The truth hurts a lot, especially when just learning the basic skills.
4) Don't be in a rush to start selling knives. Only start when the bugs are worked out and people who know knives think they are good. As a general rule, I never met a new maker who didn't think his third knife was super good. The same folks a year later would be embarrassed if that same knife was ever sold with their name on it.