From a rationalist perspecive, the ad is justified. He is effectively capturing the majority of the market possible through adwords. So what's next? It makes sense to take your know-how in one market and apply it to another. The problem is that the other markets are filled with sharks. Sharks that will stop at nothing to generate leads for scammy, high-value businesses (for-profit ed, weight loss, etc)
As a moralist, one would turn their nose up at these shark-filled waters at the start. If scammy people advertise through it, why should I?
Personally, I think it's really important to dive in deep to the grey area. Not because you can make more money, but to better understand the inner-workings of the "dark" side of the business. Most of the successful players there use a slathering of evil techniques combined with a wealth of direct marketing experience that whitehat marketers use every day.
It's important to test -everything-, learn as much as you can from empirical data, and then move forward with both your knowledge and moral compass in mind.
I often say I have the full Zynga playbook at my disposal and the judgement to know when not to use it.