If I don't hear back from a recruiter, should I write to them again?
A response is unlikely, but figuring out a way to follow-up in a politely persistent way every month or so might not be a terrible idea. A recruiter may not be working on filling position that matches your background, but they may be looking for someone just like you next month. The best avenue for job seekers is to network into the recruiting firm with a referral from a mutual contact.