When it comes to form fields, in most cases, less is more. Research consistently shows that fewer form fields translate to more conversions.

For instance, a case study from VMO demonstrates how the removal of just three fields led to a conversion lift of 11 percent. When Blivakker, a Norwegian online beauty shop, cut their fields down from 17 to 14, they saw an 11 percent increase in registrations.

Another study, by research lab Marketing Experiments, shows similar results. David Kirkpatrick describes how Marketo cut its nine-field form to seven fields, resulting in a 20 percent increase in conversion rate. When they cut the form down to just five fields, the conversion rate increased by 34 percent.

In most cases, all you need to ask is for the visitor's email and password. You can get the rest of the info later.

In the above example, the headline, body copy, graphics, form, and call to action are all supportive of the main the page’s main goal: a 30-day landing page conversion course.

In addition to using fewer form fields, make your forms overly simple to fill out. This will spare your users their time, making it more likely that they’ll convert.

There are many ways to accomplish this. For example, if you need an address, ask for a zip code, and the city and state are already filled out! Or use a drop down menu that predicts the outcome so visitors can move through the form faster.

Idealist.com provides a dropdown like this which completes the city, state, and country for users so that it’s easier for users to input their location.

Sometimes conversions result from the quality of the copy itself. Though you can’t influence leads much with in-field copy (name, email address, etc.), you have a great opportunity to persuade them with the headline and surrounding copy. This is what directs user attention to your signup form in the first place.

Content Verve performed a study on persuasive form copy, and found that demonstrating benefits, relevance, and value dramatically increases conversions. By adding relevance and value to a newsletter sign-up form, the company boosted conversions by 83.75 percent.

In addition, including benefits (see: "Get FREE Betting Tips", and “Get the Best Daily Tips") increased conversions by 31.54 percent.

Marketing tactics work best when they’re based on sound, psychological principles. For instance, B.F. Skinner’s operant conditioning works on the idea that behavior that gets rewarded is reinforced, while behavior that gets punished is deterred (and eventually eliminated).

Let’s take a look at how that plays out on the signup form…

This image represents the pop-up windows for TheSkimm newsletter signup. As site visitors go to close out, the form appears, showing just one field for the visitor’s email address, and supporting copy that plays off of this concept: “No thanks, I prefer to be miserable in the morning.”

This tactic works to deter users from leaving without submitting their email address in exchange for the newsletter.

Another psychological trigger used here is social proof. By showing people that “millions of others” have signed up, users are even more inclined to participate for fear of missing out. Content Marketing Institute does this as well:

Testimonials have the same effect.

Two or more columns gets confusing for visitors when tabbing, so make your forms single-columned for better ease of use.

Plus, natural user behavior is to scan a page from top to bottom. The single-column form layout promotes this pattern. Added bonus: This form design performs better on mobile devices.

When the signup process is more efficient, leads and conversions will naturally increase.

Creating the perfect web form is at the intersection of design, user experience, and marketing psychology. All three areas are closely related when it comes to conversion rate optimization, so marketers of all stripes should be familiar with these best practices.

To secure more conversions, whether a lead capture or outright sale, remember to use: