May two people surf the same account?

This is generally frowned against.  We do not recommend sharing your password with anyone.  If we detect more than 1 person has logged into your account you may risk having your account blocked for a period of time.  Due to Security Restrictions.  If TrafficBrowser Click Contest is active you may risk having all or some of earned clicks reported to TrafficBrowser forfited.  We have no control of Traffic Exchange sites, if they detect more than 1 person surfing at the same time you could loose your account according to their TOS.  So as a general rule don't share accounts.