Here's a question for you...
Do you like to wait for a whole series to come out before you start reading? Or are you willing to wait years between volumes?
I generally like to know they are all available, even if I don't have them on my shelf. Though this doesn't always happen. I've started ready A Song of Ice and Fire but will now wait for the series to be complete. I gave up on Wheel of Time at number 5 and haven't gotten back to it yet (though I intend to).