Job boards, general postings, online listings, job fairs... most people find their first few jobs that way, so that's certainly not a red flag.

But a candidate who continues to find each successive job from general postings probably hasn't figured out what he or she wants to do -- and where he or she would like to do it.

He or she is just looking for a job; often, any job.

So don't just explain how you heard about the opening. Show that you heard about the job through a colleague, a current employer, by following the company.... show that you know about the job because you want to work there.

Employers don't want to hire people that just want a job; they want to hire people that want a job with their company.