WPP-Oxford Study: 84% of Purchase Decisions Are Made Before Shopping Starts

What the WPP-Oxford Research Found About How Consumers Decide

A major new study from WPP Media and Oxford University's Saïd Business School has upended a common assumption in advertising: that the best moment to influence a consumer is when they are actively shopping. The report, titled How Humans Decide, analysed more than 1.2 million purchase journeys across 47 countries and over 200 product and service categories. Its headline finding is striking — 84% of consumer purchase decisions are effectively made before people even begin shopping.

The mechanism behind this is what the researchers call "priming bias" — the combined effect of existing familiarity, brand affinity and a preliminary judgement formed from the options a consumer already has in mind. The data shows that people are 10 times more likely to consider a brand they are biased towards, and 14 times more likely to buy it. The average shopper considers just two or three brands per product category, and those are almost always the ones they already view positively.

This pattern holds across every category studied, from appliances to food, suggesting it is a fundamental human response to overwhelming choice rather than something marketing can easily override. The implication is that brand-building communication — not last-minute sales conversion — is the essential groundwork for earning a place in a shopper's shortlist, and that this work must begin long before a purchase is contemplated.

The research also found that consumer receptivity to advertising varies enormously. About 10% of people are open to almost any form of brand communication, while 23% are largely unreceptive to all marketing. The single biggest factor determining receptiveness is the product category itself: buyers of home appliances are typically nine times more receptive to marketing than the average person, while toothpaste buyers are five times less influenceable.

Why Reach Is Not Influence — and What the Advertising Industry Gets Wrong

Why the Advertising Industry's Reach Obsession Is Costly

The report's most commercially significant finding is that reach and influence are not the same thing. Selecting four touchpoints based on reach alone yields only about a 20% chance of affecting a purchase decision. Selecting the four most influential touchpoints — those with the highest probability of shifting brand perception or driving a sale — raises that probability to 47%. The reach may be identical; the outcome is not. For context, this distinction matters enormously at scale, because media budgets are still overwhelmingly planned around reach and frequency metrics.

Where the Money Is Being Wasted

If 84% of decisions are pre-made and the average shopper considers only two or three brands, then advertising aimed at capturing consumers mid-purchase is largely speaking to people whose minds are already settled. The research suggests that most consumers normally considered "not in the market" should in fact be the principal audience for advertising — and that the focus should be on building brand preference rather than harvesting immediate sales. This is a direct challenge to performance-marketing orthodoxy, which has dominated budget allocation for the past decade.

The Category-Specific Reality of Influence

Touchpoint effectiveness varies dramatically by product category. In personal care, word of mouth has a 58% probability of influencing a purchase. In the supermarket category, that same touchpoint has just a 2% probability. A tactic that works for washing machines may have little impact on shoe buyers. This means there is no universal playbook — and companies that apply a single media mix across diverse product lines are likely embedding significant waste. The research also shows that owned channels (company websites), shared channels (influencer content) and earned channels (word of mouth) can be nearly three times more effective than paid media at driving final purchases.

The Shift Toward Earned and Creator Channels

The data confirms what many in the industry have suspected: social media influencers and creators have increased in influence by 54% since 2020, while social media overall has risen by 143%. These channels are not just growing — they are disproportionately effective at the conversion end of the journey. For brands with heavy paid-media dependencies, this represents both a strategic opportunity and a structural risk to existing agency and media-buying models.

What This Means for WPP and the Agency Business

WPP Media's involvement in the research is itself notable. As one of the world's largest advertising groups, WPP has a commercial interest in demonstrating that sophisticated, influence-based media planning delivers better outcomes than blunt reach buying. If advertisers internalise the report's findings, demand could grow for agencies that can map receptivity and touchpoint effectiveness at a granular, category-specific level — capabilities that require significant data and analytical investment. Agencies unable to offer this may find themselves competing on price alone.

What Marketing Leaders Should Do Differently

The single most important insight: if 84% of purchase decisions are made before shopping begins, then the majority of advertising spend aimed at in-market consumers is reaching people whose minds are already made up.

For marketing leaders and brand strategists, the research points to several concrete shifts:

• Audit your media plan against influence, not just reach. The report shows that selecting four touchpoints by influence rather than reach raises the probability of affecting a decision from 20% to 47%. Ask your agency or media team to rank current touchpoints by measured influence within your specific categories, not by impressions or CPM.
• Reallocate toward owned, shared and earned channels. These can be nearly three times more effective than paid media at driving purchases. If your budget is heavily weighted toward paid, test a meaningful shift toward creator partnerships, word-of-mouth programmes and owned digital properties — particularly in categories where word of mouth scores highly (58% influence in personal care, for example).
• Map receptivity by category, not by audience demographic. Appliance buyers are nine times more receptive to marketing than the average person; toothpaste buyers are five times less. If you operate across multiple categories, a single media strategy is almost certainly misallocating budget. Build category-specific playbooks.
• Start brand-building earlier than feels comfortable. If the average shopper considers only two or three brands and those are the ones they already favour, the window to enter that shortlist closes long before a purchase intent signal appears. Invest in upper-funnel brand communication in the months and years before consumers are in-market.
• Track social and creator channel effectiveness separately. Social media influence has risen 143% since 2020 and creator influence by 54%. These channels warrant dedicated measurement rather than being folded into broader digital spend.

Metrics worth watching: your brand's inclusion rate in consumer consideration sets (the "top three" metric), the influence-weighted performance of individual touchpoints by category, and the ratio of brand-building to sales-activation spend over the next 12–24 months.