> 1) The advantage over the personal homepage is that more people will see it. Would a video get more views on your blog or on a video sharing site with lots of content where people went to find content like that?

In the world of Google Scholar, this isn't true. Google Scholar indexes scientific papers and aggregates PDF links, without regard for what website the PDFs came from. If no one cites your paper and it's not in a journal I follow, I probably won't read it anyway. If I am sufficiently interested, when I search Google Scholar, the PDF link on your personal website will be as accessible as a PDF link anywhere else. (It may even be more accessible. If, as others have suggested, Academia.edu doesn't let you download PDFs without registration, then PDFs uploaded to Academia.edu probably don't get indexed by Google Scholar.)