There are several key performance indicators (KPIs) to measure in order to gauge the success of a marketing campaign:

• Traffic and engagement metrics – Measure website visits, social media reach/engagement, email open rates, etc. This indicates how well your campaign messaging and content is resonating.
• Lead generation and conversions – Track leads captured, form submissions, phone calls, sales inquiries, sign-ups, purchases/transactions generated from the campaign. These show direct business impact.
• Brand awareness and sentiment – Use surveys and online listening to measure changes in brand recall, favorability, consideration that may result from the campaign.
• SEO rankings – For campaigns involving SEO, track keyword ranks to see changes in site visibility and authority.
• Referral traffic – Check referral channels to see which are driving increased visits and conversions during and after the campaign.
• Cost per lead/customer acquisition – Calculate cost vs. return by dividing total campaign spend by the number of leads or sales generated.
• Lifetime value of acquired customers – Gauge the longer-term value of customers acquired through the campaign by tracking repeat business, referrals, social shares etc.
• Channel engagement and performance – For multichannel campaigns, compare engagement and conversion rates across channels to optimize spend.
• Audience insights – Campaigns often reveal new insights into customer demographics, behaviors, interests etc. which can inform future efforts.

By setting clear benchmarks and tracking both quantitative and qualitative data, you can holistically measure marketing success and demonstrate ROI.