Online advertising faces significant challenges from advertisement fraud, which involves activities like botnet traffic, fake referrals, and fraudulent clicks that can cost businesses billions annually. This type of fraud gives the illusion of a successful ad campaign but fails to generate real revenue, as seen in cases like Aleksander Zhukov's "Methbot" scheme and Uber's litigation against ad networks. Fraudulent tactics include hidden ads, clickjacking, click flooding, fake app installations, and botnet fraud, all of which exploit the digital advertising ecosystem. To combat these threats, advertisers are encouraged to implement strategies such as blocking malicious users, managing Ads.txt and Sellers.json files, and monitoring data for anomalies to ensure genuine engagement with their ads. Tools like Fingerprint's BotD can help developers build applications that detect and prevent fraud, enabling businesses to safeguard their advertising investments and focus on effective marketing strategies.