Brand & Account Context
Onparts.gr operates one of the largest Google Ads accounts in the Greek automotive parts market.
The account manages:
- Thousands of SKUs
- High daily spend
- Continuous demand across brand, category, and product-level searches
- Strong dependency on Search as a primary revenue driver
At this scale, Smart Bidding is not a “toggle” — it is a system-level decision with real operational risk.
This case focuses on how a large, revenue-critical account was successfully migrated to Smart Bidding, without sacrificing stability, efficiency, or control.
Awards
The Challenge
The Core Challenge
The challenge was not whether Smart Bidding could perform — but how to introduce it safely.
Key risks included:
- Learning phase volatility across high-spend campaigns
- Over-optimization toward short-term signals
- Inconsistent value distribution across categories
- Loss of control in campaigns with mixed intent
- Smart Bidding amplifying poor structure instead of fixing it
The objective was to let the algorithm do what it does best, while still enforcing strategic constraints.
Smart Bidding Readiness Framework
Before activating any Smart Bidding strategy, the account went through a readiness audit.
- Signal Quality & Conversion Hierarchy
We redefined what “success” meant at campaign level:
- Primary conversion actions were isolated
- Secondary signals were excluded from bidding influence
- Conversion value logic was aligned with real business value, not volume
This ensured Smart Bidding was optimizing toward meaningful outcomes, not inflated signals.
- Campaign Role Definition
Each campaign was assigned a clear functional role, which dictated the bidding model:
| Campaign Type | Role | Smart Bidding Strategy |
| Brand Search | Demand capture | Target ROAS |
| Category Search (high volume) | Scale | Maximize Conversions |
| Category Search (value-driven) | Profitability | Target ROAS |
| Long-tail / SKU queries | Coverage | Maximize Conversion Value |
This avoided the common mistake of applying a single bidding strategy across fundamentally different intents.
Our Approach
Migration Strategy: Controlled, Not Aggressive
Phase 1 – Partial Activation
Smart Bidding was enabled incrementally:
- Only campaigns with sufficient historical data were migrated
- Budgets remained stable to isolate bidding impact
- Bid targets were set conservatively, not aggressively
This allowed the algorithm to learn without being forced into unstable behavior.
Phase 2 – Learning Phase Containment
During learning:
- Bid limits and budget caps acted as guardrails
- Performance was evaluated daily at segment level
- No structural changes were introduced mid-learning
This prevented signal distortion and false negatives during evaluation.
Phase 3 – Target Calibration
Once campaigns exited learning:
- Target ROAS values were adjusted gradually
- Budget was redistributed based on marginal efficiency, not absolute ROAS
- Underperforming segments were either restructured or excluded from Smart Bidding
Smart Bidding was treated as a feedback loop, not a one-off setup.
Advanced Smart Bidding Tactics Applied
To maximize impact at scale, we introduced several advanced tactics:
- Intent-based campaign clustering to prevent cross-learning pollution
- Value segmentation across categories with different margin profiles
- Search term pruning to protect Smart Bidding from low-quality signals
- Budget elasticity testing, allowing the algorithm to expand only where efficiency held
These ensured that Smart Bidding scaled selectively, not blindly.
Results
Post-migration, the account demonstrated:
- Increased bidding stability across high-volume campaigns
- More efficient budget allocation across categories
- Reduced reliance on manual bid adjustments
- Improved consistency in value-driven performance
Most importantly, the account transitioned to Smart Bidding without performance shock, proving that automation can scale safely when paired with strong structure and discipline.
key takeaway
Smart Bidding does not fix accounts.
It amplifies whatever structure and signals you give it.
For enterprise-level accounts like Onparts.gr, success comes from:
- Strategic segmentation
- Clear conversion hierarchy
- Controlled rollout
- Continuous calibration
When treated as a system — not a shortcut — Smart Bidding becomes a scalable performance engine, even at very large scale.







