You are asking for exp periods for selfish reasons or for the concern of bringing in new players? The difference being you advertise to bring in ppl for the weekend, or do something like mogtabs for the current player base. Once a week you can get skill up increase. increased movement speed. etc etc.
I would much rather see something like mog tablets in ffxiv then watch SE whore themselves out with double xp weekends trying to bring in even more casuals I doubt Ill even get to play with.