I think learning the top 3000 words makes it easier to get more passive help from books, newspapers and television. For me, there is a threshold when I improve without really trying, just by reading and listening. It's not the most efficient method, but I don't have to sit down and study.
Yeah, establishing that baseline of 2-3k works is what makes most of what you read comprehensible, and allows you to pick up more vocabulary and understanding through context, which I think is pretty much the key. I actually do think it might be the most effective method once you're at that level.
