I started using Answers when it first came out. I enjoyed it; I'd spend the time to come up with a meaningful response. I'd imagine I was giving advice to my younger sister or I'd use my overpriced undergrad degree to help struggling freshman w/ their econ homework. While some of the more academic areas draw knowledgeable answerers I found that as the masses discovered how fun it was to play Dear Prudie the quality of questions and answers quickly spiraled downward.
In addition to economics I enjoy perfume and beauty products. I'd answer beauty questions using my years of experience and experimentation. My answers would be left to compete with people who are clearly thirteen years old. I believe that younger people have a lot to bring to the table and I don't discount their opinions - but their answers are short, incoherent and utterly useless. It's clear that this is about racking up points and making it to the next level and not about helping. I'm proud of my 32% "Best Answers" score b/c I know for many of those answers I used a text book reference and always checked my grammar.
Haven't used Answers in 2 months - I'll answer a restaurant question every now and then but for the most part it's cluttered with junk. It's hard to connect w/ people asking legit questions and avoid having your answer from becoming lost among the "omg! my boyfreind gave me a hickee two!" (ok great, no information there) and the "idk call you're docter" (if you don't know don't answer. Learn how to use contractions.) and the "just put tooth paste on the zit" (and the bad, non derm approved) (typos intentional for mockery purposes.)