Bid Adjustments
Paid MediaAlso: Bid Modifiers · Bidding Adjustments
Quick definition
Bid adjustments are percentage changes you apply to your base bid in a paid search or paid social platform to spend more or less in specific conditions. Common adjustment types include device, location, time of day and audience. A positive adjustment raises the bid, a negative one lowers it.
Treat each adjustment as a hypothesis tied to a specific conversion pattern, not a permanent setting. Revisit whenever conversion rate or CPA shifts by segment.
How it varies across Australia
Mobile bid adjustments in Australia tend to run positive for ecommerce and negative for high-value B2B lead generation, reflecting where each type of conversion actually happens. The variance between businesses using adjustments well and those using platform defaults is wide.
Explore paid media performance across Australian industries →The common adjustment types
Raise or lower bids for mobile, desktop or tablet based on where conversions actually happen.
Adjust for regions or postcodes that convert better or worse than your account average.
Spend more during hours when conversion rate is highest, less when it's lowest.
Bid differently for remarketing lists, similar audiences or customer match segments.
What it actually means
A base bid is a single number that assumes every click is worth the same. Bid adjustments exist because that assumption is almost always wrong.
Someone searching from their phone at 11pm is not the same buyer as someone searching from a desktop at 10am. A shopper in Perth might convert at a different rate to a shopper in Melbourne. Bid adjustments let you tell the platform to spend more where the data says conversions are cheaper, and less where CPA is climbing.
The mechanism is simple. You apply a percentage to your base bid for a specific condition. Set a positive 20% adjustment on mobile and your mobile bids run 20% higher than your base. Set a negative 30% adjustment on a location and bids there drop by that amount.
Where it gets complicated is stacking. Most platforms let you layer device, location, time and audience adjustments on the same campaign. They combine multiplicatively, not additively, so three modest adjustments can produce a bid that's wildly different from what you intended. The maths compounds quietly until someone checks the actual auction data.
Done well, bid adjustments turn a flat CPA into a curve that matches where your real conversions come from. Done badly, they're a set of guesses nobody has revisited since the campaign launched.
A bid adjustment is a bet that a segment of your audience is worth more or less than your average customer. Most businesses never test whether the bet is right.
How to calculate it
Adjusted bid = Base bid x (1 + Adjustment percentage)
Worked example. Base bid is $2.00. You apply a positive 25% mobile adjustment. Adjusted bid = $2.00 x 1.25 = $2.50. Stack a negative 10% adjustment for a specific location on top and the combined bid becomes $2.50 x 0.90 = $2.25.
The Australian context
Time zone spread matters more in Australia than businesses expect. A national campaign running on Sydney business hours can be under-bidding during Perth's morning peak, which sits several hours behind. Businesses trading nationally often need time-of-day adjustments just to account for the country's own time difference, before they even think about customer behaviour.
Where people get this wrong
Related terms
Common questions
Do bid adjustments still matter with automated bidding?
Less than they used to. Target CPA and Target ROAS strategies largely override manual bid adjustments because the algorithm is already optimising per auction. Manual bidding and some Search campaigns still respect them fully, so check which strategy you're running before relying on adjustments.
Can bid adjustments be negative enough to stop bidding entirely?
Most platforms cap negative adjustments at 100%, which effectively excludes that segment from bidding. Some platforms offer separate exclusion settings that achieve the same result more cleanly than a large negative adjustment.
How often should I review bid adjustments?
Monthly at minimum for active campaigns, and immediately after any major shift in creative, offer or landing page. Seasonal businesses should also review adjustments before and after peak periods, since conversion patterns by segment often change with demand.
What's the difference between a bid adjustment and a bid strategy?
A bid strategy is the overall approach, such as manual CPC, Target CPA or Target ROAS. A bid adjustment is a modifier layered on top of whatever base bid that strategy produces, for a specific condition like device or location.
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About New Rebellion
New Rebellion is a marketing intelligence consultancy. We build tools, score Australian businesses on how their marketing actually performs, and publish Debrief every day. This dictionary is part of how we work in the open.
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