I ve just looked up change.org. They can be really successful. Some petitions of them skyrocket in Germany and lead to changed laws, better payments for nurses, the abolishment of plastic bags in supermarkets and so on (Germans really hate plastic bags

Usually you need a critical mass of at least 30.000 supporters to gain attention.
They have been several ME/CFS petitions for the last couple of years with more or less success at change.org. The numbers they generated were between 150-1800.
They are other petitions sites, even more powerful, which concentrate more on environmental and geopolitical issues. Avaaz.org is one. They often combine petitions with fund raising. They are more professional and focused, but filter their content.
Campact in Germany is so powerful, that usually over half a million people support their petitions, sometimes even millions. They are so popular, that they were able to bring very big and unfortunate laws to fall.
Change.org accepts everything. I think we should demand specifically more funding for biomedical research from the US or UK government for a start. The petition must be quite professional. A video explaining the big CFS mess would be a good idea.
The internet can be extremely powerful, if you do right. The big question is how! My biggest dream would be a kind of overview and news page, where everything comes together. An interconnection between all the charities, advocacies, patients groups and so on. Imagine what we could pull of with a site, where 20.000 ME patients come together. Crowdfunding, petitions would be so easy to start!