Fraud & invalid traffic · also called Traffic mixing
Traffic blending
Traffic blending is mixing cheap, low-quality or invalid traffic with good traffic so that the average looks acceptable and the bad part goes unnoticed.
Feed owners and providers often judge a partner by averages: overall click rate, overall conversion quality per Channel ID. Blending exploits that. A seller takes a stream of real, well-performing visitors and stirs in a share of bots, incentivised users or unapproved sources. The blended stream still looks plausible, and the seller is paid feed prices for the cheap part.
It happens at two levels. A traffic source or broker may blend what it sells to arbitrageurs. And an arbitrageur may blend what it sends to its feed provider, hiding an unapproved source inside an approved channel.
The signs appear when the average is broken apart. Segments by hour, device, placement or Sub ID show one slice with strong results and another with none. Volume rises without matching spend on the approved source. Quality drifts down gradually as the mix is pushed further.
Defence is granularity. Report and score traffic at the smallest unit available, keep each source in its own channel, and treat any partner who resists that transparency as a risk. Smart pricing and clawbacks punish the whole channel, not only the bad slice.
Think of it like this
It is a milkman watering the milk. Each bottle still looks white, and only a proper test shows a third of it is water.
An example
Say a channel sends 10,000 clicks: 7,000 genuine ones converting at 4% and 3,000 bot clicks converting at 0%. The blended rate is 2.8%, which may pass a casual check while 30% of the advertiser spend is wasted.
Related terms
Traffic laundering
Traffic laundering is passing low-quality or prohibited traffic through intermediate sites and redirects so it reaches a search feed looking clean and legitimate.
Traffic source approval
Traffic source approval is a feed provider's sign-off that a particular place you buy visitors from is allowed to send traffic to its search feed.
Channel ID (custom channel)
A channel ID is a label attached to search ad requests so that revenue and clicks can be reported separately for each page, campaign or traffic source.
Sub ID
A sub ID is a custom label a publisher passes to a feed or network with each visit, so reported revenue can be broken down by that label.
Smart pricing
Smart pricing is Google's system for automatically lowering what an advertiser pays for a click on a partner site when that click is less likely to lead to a sale.
Traffic quality score
A traffic quality score is a rating of how genuine and commercially valuable a publisher's visitors are, used to decide what their clicks are paid, or whether to keep them.
Sources: Google AdSense Help: Policy violations in scope for Restricted Access Features (RAFs)