My mileage varies heavily - I'm using LinkedIn as a main source for open positions, and it's 90% what OP describes. There are positions listed by, let's say, a

My mileage varies heavily - I'm using LinkedIn as a main source for open positions, and it's 90% what OP describes. There are positions listed by, let's say, a local insurance company, but they are, as you say, boring - so they just post the job offer and wait for candidates. Recruiters post a job, then post that same job with 5 other titles, then repost all of these twice per week to bump them up in the candidates' queries.