I hit a peculiar problem with Cinderella Girls, which gave me just enough excuse to stop grinding. It appears that Mobage created me 2 game profiles in CG, attached to my user account. When I log in, I get one or the other depending on the device that I use. The problem is, every new device I try gets account #2, whereas all my high-level idols are attached to the account #1, which I had first. Thus, I operate under a threat of naturally losing access to all the virtual treasures as the old gevices get out of circulation.
One of the legacy devices is actually my laptop, so I can experiment with cookies on it. But meh. It probably is the time to draw the line. I started playing in November, so the game lasted me 6 months. I spent about $80 on it. Not bad, and about comparable with better games for dedicated handhelds.
UPDATE: Coincidentially timed strip at Penny-Arcade, where Tycho says: "No, because they're not real cards, we don't actually own them, and the moment they decide it's not worth it anymore the entire game will evaporate."