Free forums for users can be that

[user_not_found]

There is some sites which offers to users the ability to create (phpBB.) forums free and have their own areas logos personal themes e.t.c
of course the forums are in like sub forums of main forum- site example
myforum.mainsite.com
Can be that with vbulletin?

[Bradley_Wint]

No.

vBulletin copies are licensed per copy...

meaning... a person has to buy a license for each copy of vb they are running on a server. Obviously phpBB can do that because phpBB is free to the public. There are sites that do vBulletin sub hosting but there are payment terms in place. You would have to contact vBulletin to work out an agreement for sub foruming.

[Dismounted]

# vBulletin license grants you the right to run one instance (a single installation) of the Software on one web server and one web site for each license purchased. Each license may power one instance of the Software on one domain. For each installed instance of the Software, a separate license is required. Modifications to the Software or database to circumvent the one-license-one-board rule are prohibited.
# The Software is licensed only to you. You may not rent, lease, sublicense, sell, assign, pledge, transfer or otherwise dispose of the Software in any form, on a temporary or permanent basis, without the prior written consent of Jelsoft.
http://www.vbulletin.com/order/license_agreement.php