From time to time I get unsolicited job queries, mostly through social networks like LinkedIn. Sometimes they are quite interesting and offer jobs in big respectable companies. But at the moment, I'm not interested at all in changing my job. Should I reply to such an interesting offer, just saying politely something like "the job is interesting, but at the moment I'm not considering changing my job"? Or just ignore it?
What do recruiters expect in such a case and what is considered polite? And is there any real benefit making contact with a recruiter in this case? Perhaps to have better prospects if I'd ever apply in the future for the company?