I suspect some selection bias here, so my datapoint is "tried multiple times, didn't get anything useful out of this".
Once contacted company which happened to be geographically close to where I live. Eventually they said they had a "tremendous influx of candidates for that position", so for me it didn't work out.
It's easier to get to talks in "work for a startup" program - I think that's because that program is more structured, not just "looking for work/looking for workers" generic board.