The exposure rate takes into account the time spent on a zone. If a user scrolled through a zone very quickly, it will not be taken into account in the exposure data.
A zone can only be considered "exposed" if it has been displayed for at least 150 millisecs.
How it's calculated
Exposure Rate = Number of pageviews that displayed the mid-height pixel line of the zone for at least 150 millisecs ÷ Number of pageviews.
Note: We collect and show exposure metrics based on 100% of traffic.
How to interpret it
What percentage of my traffic sees the content all the way to the bottom of my homepage? Do visitors see the cross-sell at the bottom of my product page?
There is a low Click Rate on my cross-sell — is this due to a lack of attractiveness, or is it because visitors are not exposed to it?
Exposure rate shows that the second row of products is seen by half as many users as the first. Consolidating into a single row of 6 products could ensure your content is viewed by more visitors.