Definition
The decoy effect (also called the asymmetric dominance effect) is a cognitive bias where consumers change their preference between two options when a third, asymmetrically dominated option is introduced. The decoy is priced to make one of the original options (the target) look more attractive.
In email marketing, the decoy effect is used in pricing emails and product comparisons to guide subscribers toward a specific offer without forcing them to choose it.
How the Decoy Effect Works
| Options Presented | Decision |
|---|---|
| Option A: Basic (£10/month) | Hard to choose — each has different benefits |
| Option B: Pro (£20/month) | |
| Option A: Basic (£10/month) | Option B becomes the obvious choice |
| Option B: Pro (£20/month) | |
| Option C (Decoy): Pro Light (£18/month, fewer features than Pro) |
Decoy Effect in Email
| Offer | Decoy | Target | Why It Works |
|---|---|---|---|
| Monthly: £30 | Yearly: £300 | Yearly at £300 (seems high) | No — this needs a different structure |
| Web-only: £10 | Print-only: £15 | Print + Web: £15 | Print + Web at same price as Print-only makes it the obvious choice |
| Basic: £50 | Premium: £150 | Standard: £100 | Premium decoy makes Standard feel reasonable |
How to Use the Decoy Effect in Email
- Place the decoy next to the target: The decoy should be positioned adjacent to the option you want subscribers to choose.
- Make the decoy clearly inferior: The decoy must be visibly worse than the target option — higher price for fewer features or same price for less value.
- Use in plan comparison emails: When presenting pricing tiers, include a decoy tier that makes your target tier look like the best value.
- Test decoy structuring: Different decoy structures (higher price, fewer features, different positioning) produce different results. Test to find the most effective configuration.
Examples by Email Type
| Email Type | Decoy | Target | Result |
|---|---|---|---|
| Upgrade email | Premium (£200/month — too expensive) | Standard (£100/month) | Standard feels reasonable by comparison |
| Purchase email | Basic (£10 — limited features) | Pro (£20 — decoy: Pro Light at £18) | Pro looks like best value |
| Bundle email | Single product (£30) | Bundle (£50 — decoy: Bundle without bonus at £50) | Bundle with bonus looks superior |
Was this useful?
Related Glossary Terms
A/B Testing
A/B testing in email marketing is the practice of sending two variations of an email to a small sample of your list to determine which version performs better before sending the winner to the remaining subscribers.
Abandoned Cart Email
An abandoned cart email is an automated message sent to customers who added items to their online shopping cart but left without completing the purchase. It is one of the highest-converting email types in ecommerce.
AI Email Summary
An AI email summary is a short, machine-generated overview of an email's key points, shown by Gmail, Outlook and Apple Mail before a recipient opens the message. It is reshaping how email marketers think about subject lines, preview text and open rates.
AI Inbox Summary
An AI inbox summary is an AI-generated digest that condenses unread email — often highlighting news, actions and senders — changing how clearly your marketing email reaches and engages subscribers.
AI Inbox
An AI inbox is an email client that uses artificial intelligence to summarise, sort, prioritise and sometimes answer emails before the human recipient reads them. It is transforming email marketing metrics and copywriting.
AI Overview Email
An AI overview is a short, automatically-generated summary of a topic shown in AI search results, often drawing on and citing sources like email marketing content.
Frequently Asked Questions
Yes, the decoy effect is one of the most well-replicated findings in behavioural economics. Pricing emails using decoy framing consistently outperform straightforward pricing presentations.
The decoy effect is ethical when the decoy option is a real, available product or pricing tier. It becomes unethical when the decoy is designed only as a comparison tool and is not genuinely available for purchase.
A/B test pricing emails with and without the decoy option. The test email includes the decoy. The control email shows only the two genuine options. Measure conversion rate for your target option.
It works best for products where consumers make relative comparisons — pricing tiers, subscription plans, and product bundles. It is less effective for standalone single-product purchases.
Making the decoy too obvious or inferior. If the decoy is clearly designed to be unattractive, it can feel manipulative. The decoy should appear to be a reasonable option, just not the best one.