Thank you for reaching out to the Constant Contact Community. That's a great question. It will depend on the exact kind of data you are trying to collect. You can use the Advanced Search option to narrow down contacts on some things. You can find those instructions here. If you are looking for advanced reporting on sent emails, that's a feature that isn't yet available, however, we are tracking the request and I would be happy to add your feedback to it. If you would like to provide us some more detail about what you are looking to accomplish you may send us an email at social_support(at)constantcontact(dot)com with your username, more details on the issue and a reference to this post and we can definitely take a deeper look.