I am surprised none of the replies (thus far) endorsed the above view, so I will. Yes, if you are building something that should look the same across websites,

I am surprised none of the replies (thus far) endorsed the above view, so I will. Yes, if you are building something that should look the same across websites, this is a good idea. Though it's often better to just have your own iFrames and use cross-domain communication, since your plugin will have to do its own authentication and API as well.