Absolutely free. No sign-up.
The big reason I've got my fingers crossed, though, relates to the issue that Emil and Dominik address -- the challenges of making silver gelatin emulsions a craft that translates worldwide. I have high hopes that the people who are following along, learning emulsion making, will constructively contribute to the process. I will ask that people write a bit about their experience -- both the successes and the total fails. Hopefully, post images. Offer advice on local retail outlets. If we can make a cooperative venture of the feedback, I think this will succeed beyond even my unfailing optimism and create a web learning experience that is equal to a physical workshop.
So, if there is a 'cost', the coin is your time and willingness to share .