- Published
- 8 October 2026
- Last reviewed
- 8 October 2026
How to use this glossary
Use this reference when planning a campaign or describing a freelance service. Metric names and attribution settings vary between platforms. Business examples explain concepts and do not guarantee income or campaign results.
Browse the alphabetical term index below. Select a term to jump to its definition, example and common mistake. Use the return link after each entry to browse again. You can also use your browser’s Find command to locate a word on this page. Definitions are original RDE plain-language explanations. All examples are fictional teaching scenarios.
Term index
12 terms, listed alphabetically.
- Attribution
- Call to action (CTA)
- Click-through rate (CTR)
- Conversion
- Cost per click (CPC)
- Deliverable
- Impression
- Key event
- Retainer
- Scope
- Service offer
- Statement of work
Definitions and practical examples
Attribution
Meaning: Assigning credit for an outcome to touchpoints under a defined model.
Example: A report credits a sign-up to the last eligible campaign interaction.
Common mistake to avoid: Attribution is not the same as proving that the campaign caused the sign-up.
Call to action (CTA)
Meaning: A prompt inviting a reader to take a defined next step.
Example: A service page invites a visitor to request a consultation.
Common mistake to avoid: Choose a useful, clear action rather than competing prompts with no stated purpose.
Click-through rate (CTR)
Meaning: Clicks divided by impressions, usually expressed as a percentage.
Example: Fifty clicks from 1,000 impressions gives a click-through rate of 5%.
Common mistake to avoid: Specify the platform and scope; do not confuse impressions with distinct people.
Conversion
Meaning: A defined action recorded as an outcome of interest in a particular measurement system.
Example: An advertising account records an eligible completed enquiry as a conversion.
Common mistake to avoid: Definitions vary; a conversion does not necessarily mean a sale or profitable customer.
Cost per click (CPC)
Meaning: Advertising cost divided by the number of clicks in the relevant scope.
Example: A campaign costs £100 and receives 50 clicks, giving an average CPC of £2.
Common mistake to avoid: When there are no clicks, division by zero is undefined; do not report a false zero cost.
Deliverable
Meaning: A defined output to be supplied as part of agreed work.
Example: A freelance brief specifies three edited articles and their delivery format.
Common mistake to avoid: State review rounds and acceptance conditions rather than relying on a broad description.
Impression
Meaning: A recorded instance of content or an advertisement being displayed under platform rules.
Example: One person sees an advert twice, potentially producing two impressions.
Common mistake to avoid: Impressions are not necessarily unique viewers or evidence that the message was understood.
Key event
Meaning: In Google Analytics, an event marked as important to measuring a business objective.
Example: A team marks a completed enquiry event as important in its Analytics setup.
Common mistake to avoid: Do not assume every Analytics key event is automatically an advertising conversion.
Retainer
Meaning: An arrangement for ongoing availability or services under agreed terms.
Example: A client pays for a defined monthly content-support service.
Common mistake to avoid: Clarify inclusions, limits and payment terms; a retainer is not automatically unlimited work.
Scope
Meaning: The agreed boundaries of a piece of client work.
Example: A proposal includes writing and editing but excludes video production and paid advertising.
Common mistake to avoid: Record how extra requests will be agreed before delivering unplanned work.
Service offer
Meaning: A clear description of the problem a service addresses and what it provides.
Example: A freelancer offers a structured website-content review with a findings report.
Common mistake to avoid: Specify the audience and output rather than promising guaranteed commercial outcomes.
Statement of work
Meaning: A documented description of agreed work, outputs, boundaries and delivery arrangements.
Example: A client and freelancer record milestones, responsibilities and review points before starting.
Common mistake to avoid: Its legal effect depends on the agreement and context; seek advice where needed.
A distinction worth keeping clear
A click records an interaction, while a conversion or key event records a defined action. Attribution assigns credit for an outcome under a chosen model. Credit assigned by a platform is not proof that the marketing activity caused the outcome.
Practise using the terms
A fictional campaign receives 1,000 impressions, 50 clicks and 5 recorded sign-ups. It costs £100. Calculate click-through rate and average cost per click. Explain why these figures alone do not prove profitability. Write your answer in your own notes before reading the explanation. No answer is submitted or stored by this page.
Suggested answer and explanation
Click-through rate is 50 divided by 1,000, multiplied by 100, giving 5%. Average cost per click is £100 divided by 50, giving £2. Profitability also depends on valid outcomes, revenue, fulfilment costs and other expenses. Sign-ups do not automatically equal paying customers.
Sources and scope
The sources below support the terminology and relevant context. The definitions, examples, cautions and practice tasks on this page are original RDE teaching material, not verbatim extracts or a replacement for an official standard or certification syllabus. Reviewed 8 October 2026. Author: Jefferson Otonbara Imgbi.
- Google Ads: Click-through rate
- Google Ads: Average cost per click
- Google Analytics: Conversions and key events
- Google Analytics: Attribution
Cover image: AI-generated illustrative scene created specifically for this resource.