Using interest groups inside your forms gives subscribers the ability to select which group they want to be added to when they sign up.
This comes in handy if different audiences are completing the same form. Subscribers can self-select the correct group by checking a box to opt-in to that specific group.
For example, you may want to offer subscribers the choice between receiving monthly newsletters or weekly newsletters. In this case, you can create separate groups for monthly subscribers and weekly subscribers, then enable interest groups on your sign-up form so that subscribers can select which group they want to be added to.
To set up interest groups inside your form:
Navigate to Forms and create a form. You will be prompted to select the groups you want to attach to that form. Select all the groups you want to include in your list of interest groups.
If you have already created your form, simply navigate to Forms, click on the title of your form and scroll down to where it says Subscribe to groups in order to edit the groups attached to your form.
In your form editor, click the Settings tab.
Check the box labeled Interest groups to enable interest groups in your form.
Your interest groups will appear on your form with checkboxes.
To edit the labels on your interest groups:
Hover over the interest group on your form and click the pencil icon.
Edit the text or add a description in the sidebar.
If you want any groups to be hidden, check the box labeled Hidden group. All subscribers of your sign-up form will be added to the hidden group automatically, as well as any interest group they select themselves.
If you want to enable subscribers to update their own preferences and opt in and out of interest groups, you can do so by editing your unsubscribe page. The unsubscribe page is what your subscribers see when they click the Unsubscribe link in the footer of your newsletters.