The limit that has been imposed on new users is misguided and will hurt Geni in the long run. Any person I invite to the tree now will not be able to add a single person and therefore wont see the ease and beauty of working within Geni. These are potential customers who will never experience the product. There is no incentive anymore to invite people.
The restriction should be modified to at least allow these newly invited people to be able to add some people.
Suggestion : If the tree is bigger than 100, limit the individual free users of that tree to be able to add only 25 profiles each themselves.