Let’s overlook the obvious first check to make, which is how many people are visiting that page, and take a quick look at another issue that might be the cause.
I tried to sign up this morning to a good cause – it had quite an unusual spam check, I thought – the email newsletter sign up had a range slider bar. The user has to slide the slider to the right to unlock the sign up form and be able to submit it. Except the slider doesn’t work on Android devices… To select the active state and slide, you need to long press, which opens the new link dialogue with the open link, open link in a new window, etc options.
Spam protection holds it up
We’ve all experienced someone getting hold of our business contact forms and spamming us to death with hundreds or thousands of emails, hence the need for this kind of spam protection. However, we do need to be sure that the method we choose to protect our forms is still valid from a usability point of view. There are plenty of ways to validate a new user on an email sign up form that don’t prevent genuine users who are trying to engage with your business from signing up.
It is also worth testing your email sign up on as many devices as you can (assuming your web design agency hasn’t already done this).