A suggestion for the 13th birthday coming up:
Make every account prime for 10 days. (Added to existing prime accounts, of course) I don't know how difficult this would be, perhaps just inventing a '10-day game time code' for the DDO Market, and then having a 'free item of the week' one time use code for the celebration.
During those 10 (stretching to 19 for late entries) days, veteran players could volunteer as guides to show newbies the extras they get as vips. If possible, do some advertising. With Steam if nowhere else. All my grandkids have Steam accounts and play dozens of games from there.
The theory here is that f2p is boring after the first 5 levels. Let players see what they can get for 10 bucks a month. That's less that two cups of over-hyped coffee. Or Netflix.
+Dang, won't let you edit title+