The working file on invalid traffic.

Invalid traffic drains budgets and corrupts the signals that decide where the next dollar goes. What it is, the forms it takes, how it is measured, and what a defensible count changes.

A share of every paid campaign's traffic was never human, and the platform report will not tell you which share. This chapter covers the full spectrum, from crude scripted clients to sophisticated invalid traffic, and the architecture that separates bots from customers.

Most ad fraud tools are a black box. This guide breaks down what invalid traffic actually looks like, how a single 0-100 quality score gets assigned to every visit that lands from your paid campaigns, and — the part that matters — what you actually do with the findings once a sub-source starts looking dirty.

Google credits some invalid clicks on its own and reviews advertiser claims for the rest. This is the full sequence — verify the credit, build the evidence file, file the report, and cut the source with exclusions.

Find the Taboola sites sending bots and invalid traffic, then block them in Site Blocking. A step-by-step using each click's site_id.

MGID's widget_id is the highest-resolution unit you can block. Find the widgets sending invalid traffic and stop them in the campaign Widgets tab.

PropellerAds traffic concentrates by zone_id. Find the zones sending invalid traffic and add them to your campaign's zone exceptions/blacklist.

ExoClick lets you blacklist specific site and zone IDs per campaign. Find the ones sending invalid traffic with ValidVisit and block them in Sites & Zones.

Zeropark is built around source-level optimization. Find the source IDs sending invalid traffic with ValidVisit and pause or blacklist them in the Sources tab.

Published industry IVT benchmarks tell you almost nothing about your campaigns. Here is how to measure, baseline, and monitor invalid traffic in a way that actually drives decisions.