I'm trying to figure out how to use the ExactTarget API to redirect to a custom unsubscribe page when a use clicks the unsubscribe button at the bottom of an HTML email. So far, in ExactTarget's documentation, I found something about custom "profile centers" but since I'm new to ExactTarget, I wasn't sure if this is what I was looking for. So the bottom line is that I would like to create a branded landing page on a Joomla-powered website that users get directed to when they click the unsubscribe button on the company emails. All this needs to connect to ExactTarget as well. In the documentation, ExactTarget talks about SOAP API and AMPscript and all this stuff I've never heard of. Is all this necessary or can a custom unsubscribe page just be written in PHP?
Honestly, your best bet for a quick, no mess user friendly solution is to use their Smart Capture capabilities on an ET landing page - unfortunately this means it has to be hosted via Exact Target though, and not your web host. Custom Unsub page with Smart Capture
If you just are looking to get it branded, talk to Global Support or your Account Executive and see because I believe they allow some customization options (depending on your contract) to include your logo, and color scheme, etc.
I am not entirely sure it is a good idea to host an unsub page without using ET's landing page functionality(AMPScript), but if you were to create a purely custom profile center page, you need to build out a fairly intense back end with API calls connecting your server with the Exact Target server. I am sure you COULD use PHP to compile the data and then use a SOAP call of the PHP info to ET to update the data extension or list, etc. Will likely require at least Automation Studio on each account this will affect. ET Documents on Custom Profile Center
But you will also need to work with global support to change your default profile page off of what currently exists to your new page so the personalization string fills correctly when inserted.