1. Only works on some content
At first when i bought it, it only worked with native Joomla content. This was not explained at the description. "Some content" can mean anything, and I needed it for articles in Myblog. This was fixed with a new version, after some debating back and forth with the dev. But buyers should be aware about this limitation.
2. Registered users still get the pop up
the description asks "Want more sign ups to your Joomla website?".
So, would you expect the pop up to be activated for registerred users AFTER their sign up? I certainly would not. this means that if you have a community site for example, you cant use this, unless you want to aggrivate your users with the pop up when they are logged in.
I did talk to the dev about these issues, suggesting that he revised the description, but he thinks I am way off. However, I think these points are valid to many Joomla users, so judge for yourself.
As explained to this customer already, this is a content plugin. Which means it works using content tags for all Joomla content as well as 3rd party extensions that support content plugins. Content plugins are not login or user account driven. This was a misunderstanding and an assumption made by this customer of how content plugins operate and work on a Joomla website. We tried to explain this many times but he obviously did not understand how these types of content plugins work.