Blogsome was not putting the links to the theme author’s website, till recently.
Initially I was not happy with them removing the links to the original theme authors.
When I contacted them, they said they are giving the credits in their themes page, but they cannot keep the link at the footer.
I was not satisfied with the answer and I asked them to not use any of my themes thereafter.
I dont know what happened to them, but nowadays they are giving the credits to the theme authors on the footer.
Whatever may be the reason, they are on right track now.