Great question.

I'll put in my two cents. The first step is to identify your target audience. Once you have your target audience, focus your time, energy and resources of targeting that particular buyer. Me, personally, I like to put money into people. So, I love the model that includes paying individuals to go out, shake hands, meet local business leaders, and be the advertising, marketing, and sales engines for your company.

My issue with utilizing advertising is that you're (1) unable to track the majority of it, and (2) you're unable to facilitate a buying decision with an advertisement. Those two issues pose a problem. If you were trying to pull the plug or invest more, you wouldn't actually have a clue how to adjust as you have no metrics to measure success/failure by. The other side of that coin is how many sales opportunities were missed by someone (a human) having the ability to walk that prospect directly into a sale.

It is an old school method, but surely does get you the greatest ROI and prioritizes people.

Best wishes,