Hi
This is 2 security contexts + an admin context. So yes you can use 2 contexts for customers. From a Pix 515E running v7.x
pixfirewall# sh context
Context Name Interfaces URL
*admin Ethernet0,Ethernet1, flash:/admin.cfg
Ethernet2,Ethernet3,
Ethernet4,Ethernet5
customer1 (not entered)
customer2 (not entered)
Total active Security Contexts: 3 **** Three contexts allowed.
Try to create a 3rd customer context and it fails.
pixfirewall(config)# context customer3
Creating context 'customer3'...
Cannot create context 'customer3': Exceeded licensed limit on maximum number of security contexts...
ERROR: Creation for context 'customer3' failed
HTH
Jon