Blizzard has directly admitted that box sales were low for DF.
We don’t get exact numbers for WoW subs precisely the numbers are so low, too low for Blizzard to want to admit.
Cross-faction groups were enabled. Then auction house consumables were merged. Now cross-realm trading is coming. Why? Because this has to be done to keep the game alive as the playerbase shrinks.
I went to the Darkmoon Faire and didn’t see a single other player. Friends lists are empty. Guilds are empty. Trade chat is silent. No work orders. Zaralek Caverns is empty. I can see for myself that there are fewer players, even fewer than SL.
There’s no official data to show that sub numbers are good, either.
All we have is Blizzard’s admission that DF box sales were poor.