As Zynga develop new games, it seems like vampire wars is being left behind. It's not surprising why a lot vampire wars enthusiast left the game. Just read my post Why Vampire Wars is not popular anymore. But as far as I know Vampire Wars tried to keep up with a lot of improvements. Sadly the player population continues to drop. Based on Appdata Vampire Wars is number 18 in Zynga's Top 20 games in facebook.
Vampire Wars monthly user 680k and Daily User 100k is not that bad, But I'm pretty sure that as time goes by vampire wars player will continue to drop.