The viability of pay-per-click depends on your business, product, and a metric called Cost per Acquisition. The average business only completes a sale on 2-10% on their ads, but they still spend money on each click.
You’ll have to balance your cost per acquisition with your hard costs and margin to see if pay-per-click is viable. While there may be guides in your industry that encourage or discourage pay-per-click, the only way to know for sure is to create, optimize, and experiment on your ads.