[tetsusaiga]

The idea is because it's happening at scale. If you're getting hundreds or thousands of customers per day, the likelihood of this happening gets lower by some statistical proportion, especially if you don't have the organic exposure.

Also, definition of working: You make more than you spend, and if you stop the ads, you stop making as much.

That said, I'm not arguing for 100% accuracy either. It's certainly not. Simply that it's possible to be more accurate than not, which leads to profitability.

One more also- a comment above about how I failed to mention I'm not talking about paid search ads so much as other types like FB, YouTube, banners, etc.