Welcome to the Q&A Forum

I prefer to think in terms of the audience where the backlinks are coming from. Will they be interested in what I have to offer? If not I don't see a massive amount of value in that link, so Google probably wouldn't either if they found a way to accurately judge that in their algorithm. I bet they're already capable of doing so by tracking bounce rates from links, and whether anyone bothers to click them. Of course there are exceptions; no one would say no to a massive viral hit that resulted in hundreds of links. Just think about whether it seems natural or not - Tom gives some good examples. With your own examples, an accountant could have written about celebrity finances and a lawyer about how the colour of their office improved client's success rate in court...but again are these links for links sake or targeted to an audience who might be interested in your product?