It's tough to generate revenue that isn't through ads.
That said, if the users could organize into special interest groups and create a walled-garden with default no ads, and then gate-keep advertisers to a permitted white-list.
You want the unemployed to pay? Or do you want the employers to pay? If you want the employers to pay, how do you attract enough attractive unemployed to your site?
Well I guess we have a possible reason why LI is still relevant.
This suggest then that the relevance of any solution would need to appease the employers... yet here we are trying to build/design something for employees first.
We have the ability to vibe these things over a weekend, yet getting to the critical mass/tipping point of adoption is something else.
Whatever happened to: if you build it, they will come?