This seems like an extremely strange way to approach free-trials to a paid service. You would think that you would want to give customers as close to the authentic experience as you possible can. With that being said, I have known many "signal providers" to do exactly as you are suggesting so I think that would be a fine idea.

As long as the information is profitable and successful then nobody is going to complain. If you are worried about cheapening your product as you have eluded to, then I would suggest splitting the streams and offering a free-trial with one of them. Is this something you are going to make happen? I will be interested in this if that is implemented.