All of those mentioned above (including Geni and others)
are commercial software.
each of them is trying to get more paying users and the differences between them are the main reason for people transferring their tree from one to another - or even worse - managing duplicate trees.
i don't think there is a "scientific" answer to your question due to many duplicate trees, sub-trees and profiles.
about how many users - there are paying and non paying users, and every software provider will like to keep this info secret...
I am using Geni and MyHeritage. It is kind of problem, when people copy trees from one site to another. In MyHeritge there is at leat one 100.000 profile forest from Geni and another tree with lots of profiles added by me. It makes lots of useless matches. I think we should not copy trees from one public site to another.
I have found lots of connections in Geni, but most of them too remote to be really interesting. MyHeritage accepts only 250 profiles free, so it is pretty useless, if you dont want to pay. Good reports available in My Heritage.
Thanks for your replies.
The reason I ask is because my tree here on Geni is not yet linked to the big world tree. Mainly because I am not sure I want everyone looking at it.
I was looking online at other World Trees and came across One Great Family, a website that says that is is constantly searching and adding new connections to your tree.
QUOTE: "Our system continuously searches every name in your family tree for new connections.
OneGreatFamily’s automated search engine continually looks for additional information and relatives for every one of your ancestors at the same time. You will be notified by email when new information is available for your family tree." END QUOTE
So I was wondering if this as far as a search tool was benificial to users or if anyone had ever used this service. This is a pay service. Once you quit or don't pay, you no longer have access to your stuff.
Thanks for your thoughts.
I neglected to include a link to the full explanation of the family group. You can read it at http://wiki.geni.com/index.php/Family_Group