Hi Henner,
The section you added is really what was needed. I have some small suggestions for language improvement though:
"This will strengthen the Free Software Community and will give us a chance" to "This will strengthen the Free Software Community and give us a chance"
"offers buttons that webmaster can use" to "offers buttons that webmasters can use"
"So if you are a webmaster, please use our buttons. You can also inform webmasters about our campaign." to "If you see a website claiming that Adobe Reader is required to read PDF document, please let them know that this is not the case and point them to our website."
"The coordinators of this initiative are" to "Coordinators of the campaign are"
all the best, /Stian