I wasn't sure if this would work with my particular application because I'm using it with an extended Joomla user registration component called "JoomSuite User". JS User allows me to gather, track, and analyse additional information from my users during signup. Although I purchased this plugin (very affordable plugin, by the way), I had little hope of it actually working well with JoomSuite User.
Once installed, there are only two fields to complete: your email list name and your API key which is supplied by GetResponse. That's all there is to it.
Then, fully expecting to see errors, I ran my test registration and I was blown away at how seamless this little baby works! I cannot say enough good about it - it just works and it did not interfere with my extended user registration form at all. This powerful little plugin opens our marketing possibilities to a whole new dimension. Well done!