Click-through rate, or CTR, is the ratio of contacts that click on a link against the total that opened your email.
It is often used as a Key Performance Indicator (KPI), to measure the success of a campaign based on active engagement with the email, though it could produce subsequent success that isn’t tracked. For example, a campaign could trigger interest but not be acted upon. But the recipient may then retrospectively go to the website directly, instead of clicking in the email they received.
When should I use CTR as a measure of success?
If you are attempting to gain brand interest, CTR is a good way of seeing direct engagement with your brand; the same goes with a goal of increasing website traffic.
However, do not expect high CTRs to automatically mean better conversions. Sometimes campaigns geared to garnering interest will not have the kind of content that leads people to convert – whether this is sales or subscribers. It could also be that your landing page is not optimised for mobile, like your email campaign, and that can also hurt your conversions.