correct. Instagram is "worth" $1 Billion to Facebook, but it's worth $100 to a funeral home. But if you think about it, Instagram is worth way more than $1 billion to Google.
Don't be too sure. I'm sure there's some innovative funeral home that would be able to utilize Instagram to offer a way for mourners to document the mourning process and find closure, a way that would be worth much more than $100. Maybe not $1 billion, but more than $100 for sure. ;)
Because of the huge user base! (Of course, 95% of instagram users are already on facebook, but imagine if instagram uploaded your photos by default to G+)