Signup forms: vertical arrangement works fastest

When doing email marketing, one of the starting points is the signup form with which you hope to get tons of subscribers. From this point the whole train of email marketing gets rolling towards the end station: having the subscriber buy something, be informed of something, or becoming a (paid) member of something. The trick is to make as many people fill in the signup form, but also as complete as possible. There’s a separate challenge in there: when do you ask too little, or when do you ask too much? Is just the email address and gender enough for first-timers, or do you ask a bit more?
Next to the amount of fields to fill in by subscribers is the form layout: where to put the input fields, the labels, the send button etcetera. Also, does it need corporate styling and if yes, how much? A logo, a picture, other branding?
Below is an example of how form signups can be done right in terms of speed (source: UXMovement blog):

Two advantages stand out immediately on the left form layout: the amount of visual fixations and the visual directions. One disadvantage is the remaining vertical space, which is less than the form layout on the right. Depending on the amount of fields you choose to use, the left form layout will work better because it’s faster for people filling it in: this means the barrier for subscribing is lower which is helpful in the amount of signups.
Usability goes a long way, and things that seem small but can turn out big need the same amout of attention as all the other aspects of your email marketing campaigns. The same is true for signup forms, for which the above is a great example in terms of usability and speed.