I think we need to clarify some points here

Doug - when you refer to 10 user, are you sure you're not referring to
Act 8? Act 8 is capped at 10 users. If you want more than 10 users,
then you need ACT 8 Premium (workgroups.)

Act 6 supports more than 10 users out of the box, you just need to
purchase the correct number of licence keys from Sage.
You will need to purchase a licence for every person you want to log
into the database, because only one login at a time is permitted for
each licence you own. The key thing is you will only be able to use one
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/information-technology/5971-act-software-6-0-a.html
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=5971
computer at a time with one licence, and not use any two concurrently.

Gary.