I also use anki for german. I use a deck with 1850 cards to learn the nouns' gender.

I just pulled up my stats.I have been studiyng for almost a year and have averaged less than 2 minutes of study a day (with the average review lasting less than 2 seconds). In total it's more or less 10 hours.

It has been insanely effective. I read somewhere on HN that making extremely easy cards helps. It for sure helped me to keep the habit.