That is correct.
I would encourage my guests to pre-order their tickets through disneyworld.com, the discounts are the same (except custom guests get the option of 2 and 3 day park hopper tickets) but the custom tickets expire after the tickets are activated. If you get a 4 day ticket it will expire 4 days after it is activated. With the regular ones, they don't expire so they are a much better deal for anyone that will be returning to WDW.
Did that all make sense? I can't tell.