If you are paying any bill for ads, make sure you only pay for conversions. Ie. unless the customer actually buys your product, then don't pay anything. Eg. instead of paying $0.002 per view of your ad, or $0.10 per click of your ad, pay $6 per person who clicks your ad and then buys your product.
That way, ad fraud doesn't affect you. Plenty of ad providers allow such an option. Internally, they convert your payments per conversion into payments per click and then payments per impression, but importantly this shifts the incentive to get rid of bots to them, not you - you no longer care. The provider also has an incentive to send you customers who will actually buy your product, and to send the bots and web scrapers to their other clients.
That way, ad fraud doesn't affect you. Plenty of ad providers allow such an option. Internally, they convert your payments per conversion into payments per click and then payments per impression, but importantly this shifts the incentive to get rid of bots to them, not you - you no longer care. The provider also has an incentive to send you customers who will actually buy your product, and to send the bots and web scrapers to their other clients.