I preorder games i know i will okay. For instance i pre orderfootball manager every year, that normally soaks a couple of hundred hours of my year up, likewise with WoW expansions, i know im going to play them anyway so preorderimg makes sense yo me.
Otherwise i pretty much only buy games when they are on sale, either on steam or humblebundle.
I literally havent bought a physical PC game since, maybe, 2012.