We target Canadian small businesses (<75 employees) who aren't hiring frequently enough to have internal recruiters, job posting discounts, or fancy tools. Our shortlisting services are flat-rate and 60-90% less than recruiting agencies. Things we're already testing: content marketing, guest posting, partnering with associations & CoC's, PPC, tradeshows, and a referral program. Looking for some creative growth hacking ideas. Thanks for the input!
Another thing you should consider is public relations, or more narrowly media relations.
Identify journalists in your area that write (or broadcast) about your industry. Introduce yourself and tell them you are hoping to become a resource over time, and ask them what types of things they are most interested in/looking for. Then, actively look for items of interest to send their way--even if it has nothing to do with your business. This is critical; you want to be genuinely helpful, and not simply pestering them to cover your business. In addition, you may also "pitch" yourself as a quotable source when they are working on stories that involve broader topics about small business.
If possible, offer to meet them at their office. You might get a tour of a newsroom, radio or TV studio and see firsthand how they work.
Over time, journalists will appreciate good sources. Many journalists are overworked and underpaid, and they are grateful for "eyes and ears" who are uncovering story ideas for them. Even better, if you make introductions of other reputable sources to them, you further cement yourself as valuable in the journalists' networks. Remember, in your area what they care about most is the local impact of anything they write about...even for national/international stories, they will always be looking for a local "angle."
After developing a rapport (over a period of months and even years), it will be easier to contact these people when you have something newsworthy to share about your company.
Receiving favorable coverage in the media equates to a "third party endorsement" of sorts that is far more credible in consumers' eyes than traditional advertising and marketing.