We’ve had an issue using the iframe based integration of the twitter follow button and having callbacks working. When the iframe option is used, the callbacks specified doesn’t seem to work. Here’s a simple example that shows this - http://jsfiddle.net/imranbohoran/k7BZ8/8/
We’ve tried the anchor based approach and with that the callbacks seem to be working ok - http://jsfiddle.net/imranbohoran/kDqB8/19/
Can some one confirm if the callbacks don’t work/not supported with the iframe option?