Interesting...
In my 30+ year career as a technician then an engineer...
Through changes in the economy, relocating, going back to school, etc, I've gotten work...
1. Through direct and family friends.
2. Through recruiters.
3. By posting my resume on major job boards.
4. By replying to job offers on major job boards.
5. Through former co-workers.
6. Through staffing agencies...
Sometimes because the technology related questions for specific things I did not have much prior experience in, and hiring managers not always being confident I'd be able to learn those specifics, it would take a couple interviews where I'd fail some answers, look them up post-interview, then finally ace an upcoming interview with another company and finally get a job there.
A few times for various reasons I've been out of work for close to 6-10 months at a time. Was not always easy. I know many have had it rougher, so I'm not complaining.
However, I've not gotten a job via an online forum like this, but I'm not saying that would not be possible...