commit: fb200d8 - #595 (2014-04-14 00:44:57 -0400)
Grandma already uses Yahoo. Also that's why teens abandon Facebook, now that grandma arrived there. I don't think this question is relevant.
I am sure there are some trendy grannies out there that would use it. When I think that my mother is actually a grandma now... Yes, perhaps.
My grandma has never owned a computer, so probably not ;)I don't think that grandmas en masse will use Tumblr though, because the only reason they use Facebook (for the most part) is to keep in contact with their grandchildren and younger relatives that are on Facebook - it's the easiest way to stay updated on the lives of your loved ones.