Aweber

AWeber is a great tool for managing your mailing lists, with autoresponder sequences, simple web forms, and detailed reporting.
It also allows you to segment your subscribers according to certain criteria, either provided by themselves at signup (e.g. their age), or collected automatically by AWeber (e.g. whether they opened a previous message or not).
However, we recently encountered a problem where we needed to segment a list of subscribers based on our own criteria, which needed to be provided through the web form at signup, but not specified by the subscriber (i.e. data passed through a hidden form field).
When you create a web form in AWeber, you can add extra form fields, but you don’t have an option to add hidden fields, so you have to do this manually, as described below.