Every ad platform rejects some traffic - fraud detection, targeting mismatches, frequency caps. The question is: what happens to that rejected traffic? Most platforms just drop it. We built something better.

The Rejected Traffic Problem

When traffic is rejected, someone loses:

Traditional Approach: Hard Reject

User visits publisher site
Ad request sent to platform
Antifraud or targeting rejects request
User sees nothing (or broken ad slot)
Publisher earns $0 for that pageview

Why This Is Problematic

Publisher punishment - Not all rejected traffic is publishers fault
User confusion - Empty ad slots look broken
Lost opportunity - Traffic has value to someone
Conflict potential - Publishers dispute rejections

The Fallback Solution

PopTrades fallback engine routes rejected traffic instead of dropping it:

User visits publisher site
Ad request sent to PopTrade
Antifraud flags traffic as suspicious
Request rejected for primary buyer
Fallback activated - traffic sent to alternative destination
Publisher still monetizes (at lower rate)
Buyer didnt pay for rejected traffic

How It Works Technically

Decision Flow

Request → Targeting Check → Fraud Check → Auction
              ↓                 ↓            ↓
           [FAIL]            [FAIL]      [NO BID]
              ↓                 ↓            ↓
        Fallback URL      Fallback URL   Fallback URL

Fallback Destinations

Publishers can configure where rejected traffic goes:

Alternative ad network - Another demand source
Direct advertiser URL - Specific fallback deal
Platform default - PopTrade backup demand
Custom URL - Any destination publisher chooses

Parameter Passing

Fallback URLs receive context about the rejection:

Rejection reason (fraud, targeting, no bid)
Traffic characteristics (geo, device, etc.)
Placement identifiers

This lets fallback partners optimize their response.

Why Fallback Matters

For Publishers

No zero-revenue pageviews - Every impression generates something
Reduced conflict - Less reason to dispute rejections
Monetization flexibility - Multiple demand sources
Quality incentive - Primary demand pays better than fallback

For Buyers

Clean traffic only - Only pay for what passes filters
No guilt about rejections - Publisher still gets paid
Aggressive filtering possible - Stricter antifraud without publisher conflict

For the Platform

Fewer disputes - Both parties have acceptable outcome
Cleaner statistics - Rejected traffic doesnt pollute metrics
Sustainable ecosystem - Publishers stay happy, buyers stay protected

Soft Reject vs Hard Reject

Hard Reject

Traffic blocked completely
High-confidence fraud
Clear policy violation
No fallback possible

Soft Reject

Traffic rejected for primary buyer
Suspicious but not certain fraud
Targeting mismatch
Fallback activated

Most rejections are soft - the traffic isnt necessarily bad, it just doesnt match what the buyer wanted.

Configuring Fallback

Publisher Setup

Go to placement settings
Find TrafficBack / Fallback section
Enter fallback URL with macros
Test with sample rejections

Available Macros

{rejection_reason} - Why traffic was rejected
{geo} - Country code
{device} - Device type
{placement_id} - Source placement

Fallback Economics

Typical fallback monetization is 20-50% of primary demand:

Primary CPM: $1.00 (if accepted)
Fallback CPM: $0.30-0.50 (when rejected)

This creates healthy incentives:

Publishers want to improve traffic quality (primary pays better)
But dont suffer complete loss on rejected traffic
Buyers can filter aggressively without relationship damage

The Bigger Picture

Fallback isnt just a technical feature - its a philosophy about how ad platforms should handle the inherent uncertainty in traffic quality.

Not every suspicious signal means fraud. Not every targeting mismatch means worthless traffic. The fallback engine lets the ecosystem handle gray areas gracefully instead of binary accept/reject decisions that create winners and losers.

The Fallback Engine: How PopTrade Handles Rejected Traffic Without Losing Value