A couple months ago, I signed up to receive Transparent Language's Polish word of the day via email. What I liked about it wasn't that I was getting a single word to learn every day. I could do that with a dictionary. What their word of the day provides is not just a base word, but an example of how it's used, in all its aspective, cased-noun glory. And it includes an audio example of both the single word and the example phrase.
I'd drag the email onto my desktop and let it sit there throughout the day and glance at it when I got a chance. It's a nice small chunk of learning alongside other methods that I use.
When I first started out with Polish, these things in particular - noun case and verb aspects - were somewhat baffling to me, even though they exist to a lesser extent in other languages I speak. So the example phrases were very useful to me.
Over the last couple weeks, all the word of the day emails I've received have been examples of things I've learned outside of their emails. I've run into them either through reading Polish news, Polish blogs or just learning the lyrics to a few songs here and there.
I'm now considering unsubscribing from it because of this.
It's a nice feeling to "outgrow" one of my learning methods, for lack of a better word. I'm at the point where I can concentrate on increasing my vocabulary and not so much the grammar.