Subscribing your commenters to your newsletter with a checkbox is easy. There are a few different plugins that conveniently do this for you (I’ll tell you about those plugins in a sec).
But adding the subscription checkbox to your contact form and other forms isn’t as straightforward as with the comments form. The method that you’ll use to implement this depends on the solution or software that you use for managing your email marketing.
Let’s start with the easy one.
Adding Newsletter Checkbox to WordPress Comments Form
The easiest way to add a newsletter checkbox to your comment form is to use Danny van Kooten’s Newsletter Sign-Up plugin. All you have to do is configure the plugin to work with your email marketing provider and enable the sign-up checkbox for the comment form in the plugin’s admin.
All of these plugins can also add a subscription checkbox to the new user registration form, so your site subscribers become newsletter subscribers automatically.
Adding Newsletter Subscription to Contact and Other Forms
One of the most popular plugins to have this capability is Gravity Forms. Gravity Forms can be used to create contact forms and more. If you buy the “Business” or “Developer” license, you’ll get add-ons to integrate your forms with Campaign Monitor and MailChimp.
If you use both Campaign Monitor and Contact Form 7 plugin, then you could utilize Joshua Bettigole’s add-on. This add-on will allow you to add subscribers to your Campaign Monitor list when Contact Form 7 is submitted.
These are the only possible solutions without custom development. If you want to add a newsletter subscription checkbox to your contact or other forms for AWeber, GetResponse, or other autoresponder services, you’ll probably have to have some sort of custom developed solution. Though, it shouldn’t be overly complicated for a developer with PHP skills.