I am not sure how to call it. I mean the couple of Windows that are displayed after a user opens Firefox for the first time or sometimes after an update. That might be OK for the standard user (though I doubt that very many people will actually read that). At work I rather often do open a "new" Firefox and have to click through this... combination of changelog, tips and advertisment. It is just annoying. Please give us a possibility to just skip all of that with one click, if you feel that this has to be displayed at all.
When people open a browser they do it for a purpose. They need an answer for some question at hand. They need to work. They do not want to have to listen to the tool they need to use, happily chattering away about how cool it is and what great things happened to it since it was last opened. That's distracting and disrupts workflows.