It will almost never work to place Pay Per Click ads to a landing page where you sell something. Unless you are really world class and pick your market and product, that's not going to be profitable.
What works is setting up a lead magnet, that is something everyone wants that you either give away in exchange for their email address and permission to email them, or you sell it for a nominal amount.
Obviously the lead magnet, the thing you give away, is desired by the sort of people you want to sell to, it identifies them as having a need that you can satisfy.
So then once you have their email address, you can introduce yourself and gradually work through your offers and upsells so that after, say a year, you've made .. well the rule of thumb figure is $1 per person per month.
Ad -> lead magnet -> email system.
If you get really good at it and you have a responsive list, people will approach you with offers to your list and to "split the proceeds".