Cost Per Click (CPC) – The cost of one click from a pay-per-click ad unit (like Google AdWords).
Click-through Rate (CTR) – The number of clicks divided by the number of impressions. Used to determine how effective your ads are at inspiring user action.
Conversions – The number of converted visitors by ad or traffic source. Can be any conversion you care about, like an email subscriber, a product purchase or a download.
Cost Per Action (CPA) – The cost to get one converted user, either a purchaser, subscriber or other business-critical conversion.
Customer Value Metrics
Lifetime value (LTV) – The revenue associated with one customer on average over the entire relationship with the customer.
Gross Margin – The difference between revenue and cost; typically production costs and customer acquisition costs (also known as cost of goods sold) COGS.
Revenue – The amount of money your company takes in over a period of time.
Operating Profit – The total amount earned before Interest and Taxes (EBIT)
Cost of Goods Sold (COGS) – The costs associated with the production of goods or services and the acquisition of customers for those goods.
Purchase Rate – The rate at which visitors, subscribers or members purchase from you. Typically is measured compared to a period of time or by cohort. For example the purchase rate of new members within 30 days of joining your site.
Customer Loyalty/Referral Metrics
Net Promoter Score (NPS) – Measures, in aggregate, the likelihood of your current customers to refer your product or service.
Referral Rate – The rate at which your users refer new friends to your site.
Viral Coefficient (K) – Measures the viral growth rate and spread of your idea, app, or site.
Average Number of friends referred – The number of new users you’ll gain from each existing user, on average.
Referral conversion rate – The rate at which sent referral invitations are accepted by their recipients.
Repurchase Rate – The rate at which previous purchasers return to buy from you again.
Email Marketing Metrics
Email Open Rate – The percentage of emails opened compared to emails delivered.
Email Click-through Rate – The percentage of emails clicked-through to emails delivered.
Click-to-Open Rate – The percentage of emails clicked to emails opened.
Subscribers – The number of email subscribers you have in your database.
Cost Per Subscriber – The average cost to acquire one subscriber.
Opt-in Percentage – The percentage of your user database that have opted-in to receiving email marketing.
Undeliverable Rate – The percentage of your email opt-in subscriber list that consist of bad email addresses.
Soft Bounces – The number of email addresses in your opt-in subscriber list that return a temporary bounce message, like vacation auto-responders or mailbox full messages.
Hard Bounce – The number of email addresses in your opt-in subscriber list that return a permanent bounce, like the mailbox no longer exists.
Spam Complaint Rates – The number of subscribers who flag your email as spam in the various Webmail clients, like GMail, Yahoo! Mail, etc.
Subscriber growth rate – The growth rate of your subscriber list over a period of time.
Re-activation Rate – The rate at which previously active users, who are now dormant, can be reactivated via your email marketing efforts.
e-Commerce Metrics
Conversion Rate – The measurement of the number of conversions to the number of visitors to your site over a given period of time.
Bounce Rate – The percentage of visitors who view just a single page of your website and leave without taking any further action.
Unique Visitors – The number of unique people (or as close an approximation as your Web analytics provider can get) who visit your site in a given period of time.
Pageviews – The number of pages viewed by visitors to your website.
New Visitors – The number of visitors who visit any page of your website for the first time via a particular browser.
Returning Visitors – The number of visitors who return to your website after previously visiting.
Visits to Purchase – The average number of visits it takes for a user to convert.
Average Order Size – The average dollar amount for each order made on your site. Calculated by the dividing the revenue by the number of transactions for a given time period.
Number of Orders – The total number of transactions for a given time period.
Per Visit Value – The average value of each visitor to your website. Calculated by dividing the revenue of your site by the number of visitors in a given time period.
Time on Page – The amount of time spent by one unique visitor on a given page of your website.
On-site Searches – The number of searches performed on your site.
On-site searches per visit – The average number of searches performed by a visitor.
On-site searches per purchase – The average number of searches made before a visitor makes a purchase.
Cart Abandonment Rate – The percentage of people who start the checkout process but do not complete it. Calculated by taking one (1) minus the number of purchasers divided by the number of users who added an item to their cart.
Checkout Page Completion Percentage – The percentage of users who get to the checkout page and complete their purchase.
Average Number of Days to Repurchase – The average number of days it takes for a previous purchaser to come back and make a subsequent purchase.
Coupon Redemption Rate – The rate at which coupons are redeemed for discounts on your site.
Referring Sites
Top Referring Sites – The top traffic drivers for your website.
Transactions by Referrals – The number of transactions driven by each referring site.
Value per referred visitor – The value of each visitor from each referring site.
Bounce rate – The bounce rate of visitors from a particular traffic source.
Social Media
Facebook Shares – The number of times your content is shared on Facebook.
Twitter Mentions – The number of mentions your brand or company receives from Twitter users.
StumbleUpon Shares – The number of times your content or site is shared byStumbleUpon users.
Reddit Upvotes – The number of votes your content or site receives from the Redditcommunity.
Number of Fans – The number of people who have liked your company or brand onFacebook.
Number of Followers – The number of people who follow your updates on Twitter.
Number of RSS Subscribers – The number of people who subscribe to your blog feeds.
Online Advertising – Selling
CPM for Inventory – The average Cost per 1,000 impressions for ad inventory on your site.
Number of New Advertisers/Sponsors – The number of new advertisers/sponsors you’re adding to your roster for a given time period.
Number of Repeat Advertiser/Sponsors – The number or percentage of existing advertisers who make a repeat buy with you.
Top entry pages – The top entrance pages for traffic to your website.
Top exit pages – The top exit pages for people leaving your site.
Pageviews per Visit – The number of pageviews a user views on average while on your site.
Time on Site – The amount of time a user spends on your website.
Digital Products/SaaS
Number of Downloads – The number of product or content downloads made by visitors.
Number of Trials Started – The number of free accounts or trials started by visitors.
Number of Expired Trials – The number of free accounts that did not convert to paid accounts.