Plesk 12.x / Linux :: Where Does Resource Usage Get Its Information

I recently migrated a load of domains from a pleks 8.? install to a plesk 12 one. As part of the migration a new reseller was created but all the resellers domains got "lost". They were all there and working but not appearing in the interface.

I did some googleing and fixed this problem and can now see all the domains and when I look at the reseller plesk tells me it has 0 own customers, 0 own plans and 0 own subscriptions. However, if I look at the resources tab it tells me that 7 domains out of unlimited are being used.I just wondered where plesk get's that info from and if it is safe to delete that reseller without risking the domains getting deleted too.