...give some sort of "bonus" related to the content when it's first released.
By temporary events, I mean the Katastrophe and Shroud of Apocrea.
Worth noting is the "Dangerous Times" event, in which the danger missions were available every day.
For instance, in the Katastrophe event, if it was developed as I'm suggesting, might have some sort of "promotional bonus" in the first weeks of its release:
-A discount in the Supply Depot for Shadow defenses and Elemental weapons.
-The Black Kat prestige missions.
-Moorcroft Boxes contain pages as a bonus.
-Boosted payout for levels with Kats in them (well, Candlestick needs a *permanent* boost, but that's another story).
And then for Shroud of Apocrea...
-A discount for the preceding items in the Obsidian weapon lines.
-Obsidian Boxes contain Sigils.
-The Apocrea prestige mission.
Then, after each "promotional event" was concluded...
Kataclysm: Black Kats stay. The prestige missions related to them don't. Payouts and discounts are reverted to normal.
Apocrea: The prestige mission disappears, but the Grasping Plateau is added to "random" depths.
If you do this, there's still an event and you aren't throwing content into the gutter for months on end.
How about it?
I have to agree that it's really wasteful, but I can imagine a lot of people not liking that you can get their beloved event items any day of the year.