A KPI (Key Performance Indicator) is a measurable value that indicates how effectively a business or campaign is achieving a specific objective. In digital marketing, KPIs are the metrics used to evaluate whether activity is producing the results it is intended to produce.
What makes a good KPI?
A useful KPI is specific, measurable, and directly connected to a business outcome. "Increase brand awareness" is not a KPI: it cannot be measured precisely. "Achieve a 15% increase in organic impressions over six months" is a KPI: it is specific, measurable, and time-bound.
Good KPIs also need to be actionable: if performance falls short, it should be possible to identify what to change. Vanity metrics that look good but do not connect to business results, such as total page views without context, make poor KPIs.
How are KPIs different from metrics?
Metrics are any measurable data point: sessions, clicks, impressions, bounce rate, conversion rate. KPIs are the subset of metrics that have been chosen as indicators of strategic success. Every KPI is a metric, but not every metric is a KPI.
For example, a Google Ads account might track dozens of metrics, but the KPI for a lead generation campaign is cost per lead against a specific target. Keeping the list of KPIs short and focused prevents reporting from becoming noise.
What KPIs are used for different digital marketing channels?
KPIs vary by channel and objective:
SEO: organic sessions, keyword ranking positions, organic click-through rate, domain authority.
Google Ads (lead generation): cost per lead, conversion rate, Quality Score.
Google Ads (e-commerce): ROAS, revenue, cost per acquisition.
Social media advertising: cost per result (lead, purchase, reach), ROAS, frequency.
Content and email marketing: engagement rate, email open rate, click-to-open rate, qualified traffic.
[Screenshot: SE Ranking dashboard showing keyword ranking KPIs including average position, visibility score, and traffic estimate for a tracked domain. Alt text: SE Ranking project dashboard showing keyword visibility score, average ranking position, and estimated organic traffic for a domain.]
How many KPIs should I track?
Fewer is better. A report with twenty KPIs makes it difficult to identify what matters. Most campaigns benefit from one primary KPI that reflects the core objective, supported by two or three secondary metrics that provide context.
For a lead generation campaign, the primary KPI might be cost per lead, supported by conversion rate, total leads, and budget utilisation. When we report to clients, we structure reporting around the KPIs agreed at the start of the engagement so that progress is measured consistently over time.
Related KB articles:
• What is a Conversion in Digital Marketing
• What is ROAS and How Do You Calculate It
• What is Cost Per Lead (CPL) and How Do You Calculate It
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Frequently asked questions
How many KPIs should a small business track?
Three to five is usually enough. Pick the numbers that directly reflect your goal, such as leads and cost per lead, and treat everything else as supporting metrics.
What is the difference between a KPI and a metric?
Every KPI is a metric, but not every metric is a KPI. A metric becomes a KPI only when it is tied to a specific objective you are accountable for.
How often should KPIs be reviewed?
Check direction monthly and judge trends quarterly. Daily fluctuations are normal in digital channels and reacting to them usually does more harm than good.