Will reading serial flash memory wear it out?
There is no limit to the amount of read cycles you can do, but repetitively reading causes something called read disturb. Essentially, reading lots from the same segment without an erase cycle can cause the data to be read incorrectly, and also corrupt surrounding cells in specialised cases.

More info here http://en.wikipedia.org/wiki/Flash_memory#Read_disturb 

Most flash controllers will handle this automatically by shuffling data around, it's usually only a problem with controllerless flash such as on a microcontroller