Time on Site
A measure of the length of time a user spends on a site in 1 visit: the duration of a single session.
In theory, longer Time on Sites indicate higher user engagement, as a useful website should indeed compel a user to spend more time viewing the information contained on the site. Low Time on Site indicates a webpage is probably not fulfilling what the user is looking for.
In 2016, high ranking pages were strongly correlated with higher Time on Site. Across a broad analysis of keywords, these sites averaged around 190 seconds - a 70-second increase from the previous year.
That said, this metric needs to be considered within a wider matrix of website KPIs, because many users use the web looking for quick answers. These would be short, yet still high-quality, sessions.
Click-Through Rate (CTR)
Click-Through Rate measures how many times your webpage, email, PPC or banner ad is clicked on, as a percentage of how many times it is shown (an impression).
CTR = (clicks ÷ impressions) x 100
Generally the higher the CTR, the more effective the marketing campaign has been at bringing people to a website.
Average CTR varies greatly depending on the mode of communication: banner ads in general have a far lower CTR than the top-ranked webpage for organic search. On average, webpages occupying position 1 having a CTR of 36% (clicked on 36 times for each 100 impressions). In total, URLs ranked within the first page of the search results receive over 90% of total organic traffic.
Conversion Rate refers to the number of users who complete the desired objective of any given webpage, as a percentage of the total number of users who view that objective.
A conversion can refer to a number of different actions: it could be an ecommerce sale; a completed enquiry form; clicking on an email link; subscribing to a newsletter; downloading a PDF; and so on.
Digital marketers talk about ‘conversion rate optimisation'. This refers to a structured, strategic approach to improving website performance through optimising content, user experience design, technical layout, and so on, in line with achieving specific on-page objectives.
A good Conversion Rate is heavily dependent upon the nature of your digital objective. According to WordStream, the average Conversion Rate across industries and objective types is 2.35%, with the top quarter of websites converting at 5.31%.