Cupped tires

[scottb2460@earthlink.net]

I recently put new tires on my S4 since the previous ones were cupped. I
don't know if the previous owner failed to rotate and balance since I
understand that is the major reason tires get cupped. Are there other
factors that can lead to cupping? I just want to be on the lookout and
will check the new tires religiously, but they will be rotated and
balanced every 5k, and if they get cupped again, wanted to know what
other factors I might be dealing with.  

Scott