The 90-Day Performance Dip When Switching Agencies Is a Myth

The 90-Day Dip Myth

The conventional wisdom says switching agencies causes an inevitable performance decline lasting 60-90 days. Smart Bidding needs to "relearn." Campaign structures need rebuilding. The new team needs to understand your business.

This narrative serves everyone except you. The outgoing agency uses it to discourage you from leaving. The incoming agency uses it to lower expectations and buy time. But the dip itself? It's mostly self-inflicted.

Why Dips Actually Happen

When performance drops after an agency switch, it's almost always because of one or more of these avoidable mistakes:

• • Unnecessary restructuring: The new agency rebuilds campaigns from scratch to justify their approach, resetting Smart Bidding's learning data
• • Lost negative keyword lists: Years of negative keyword refinement evaporates when the old agency doesn't hand over their lists
• • Audience data gaps: Remarketing lists, customer match audiences, and exclusion lists aren't transferred properly
• • Tracking breaks: Changes to conversion tracking during transition create data gaps
• • Ego-driven changes: The new agency changes things for the sake of appearing active, not because they need changing

Avoidable Causes

Every cause listed above is preventable. The incoming agency should inherit the account structure, not demolish it. Changes should be iterative, not revolutionary. Smart Bidding history should be preserved, not reset.

A competent agency takes control of an existing account and makes targeted improvements while preserving what's working. If your new agency wants to "start from scratch," question why. Often it's because they have a template they apply to every account, not because your structure is wrong. This is one of the agency red flags worth watching for.

The Handover Protocol

Before your outgoing agency loses access, ensure you have:

• • 12+ months of search term reports (Google only stores recent data after the agency leaves)
• • Complete negative keyword lists at account, campaign, and ad group level
• • All audience lists including customer match, remarketing, and exclusion lists
• • Change history export showing what was modified and when
• • Conversion tracking documentation including any enhanced conversions setup
• • Scripts and automations currently running in the account
• • Feed management access and any supplemental feed configurations

You own the account. You own this data. An agency that makes it difficult to extract is telling you everything you need to know about their confidence in their own work.

First 30 Days Playbook

A well-executed agency transition follows this pattern, consistent with our first 90 days approach:

• • Days 1-7: Full audit of existing setup. No changes except critical fixes (e.g., broken tracking, overspending).
• • Days 8-14: Prioritised improvement plan based on audit findings. Begin with highest-impact, lowest-risk changes.
• • Days 15-21: Implement first wave of changes. Monitor closely. No structural overhauls.
• • Days 22-30: Evaluate impact. Plan second wave. By now, performance should be at or above previous levels.

Red Flags During Transition

• • New agency wants to pause everything and rebuild - they have a template, not a strategy
• • They don't request handover data from the outgoing agency - they're not serious about continuity
• • They blame "algorithm learning" for every dip - they're hiding behind Smart Bidding
• • They change conversion tracking in week one - they're creating a data gap that will obscure comparison
• • They don't ask about your business economics - they're going to optimise for ROAS, not profit. See when your agency doesn't understand your business.

Next Steps