blackice

The website says to only look at really high values ( more than 0.99 ) and everything below 0.90 is "low risk".

Another easy & free thing you can use is proxy detection, sites like https://getipintel.net would beneficial in preventing fraud.

Reddit should really try to proxy / VPN / Bot detection because I'm willing to bet the people on fiverr are using large proxy networks to achieve this.

Satire to an extent but also somewhat true.

You can look for proxy / hosting IPs. These bots are most likely running on servers.

Try getIPIntel.net

There are many traffic exchange sites that use automated software to click or view ads. Most of them run on server ips or they're using a proxy. http://getIPIntel.net is a free and useful service to combat bad / low quality traffic. Though to save you money, your advertiser needs to not bill you for automated traffic. It's unlikely that'll happen because the more views and clicks, the more money they'll get. You can still use GetIPIntel's api to help you pick which advertising company gives you legitimate traffic.

One of the better ways to find these people using "unofficial" APIs is to look for VPN / hosting IPs. Running all of it on their home connection is very obvious so they'll branch out and let their bots run on servers 24x7. Based on the IP address and their account activity, I think it'll be a lot easier to catch botters or at least catch the big fish.

It's nice to see people doing well after posting their projects on HN. Perhaps I should share mine but I don't want to seem spammmy about it :/

The slides mention IP reputation and a great free resource for that is http://GetIPIntel.net to make sure unexpected IPs don't connect to your services.

Something like a simple proxy / VPN IP detection should be used because I assume most of the "carders" don't use their home IPs. There are decent free solutions online like W I T C H and GetIPIntel.

I also recommend this service, been using it for awhile now and It's pretty accurate.