If you send out 1000 emails, and 100 people open it, but only 25 people decide to click on your link, this means your CTR is only 25% which is low. That means that 75% of the people reading your email weren't interested in clicking on the link.
And when we think that 25% CTR in the mailers world was considered a high CTR before Listnerds.
Really? Wow, well that's a massive win here then with Listnerds!