Ok, the word useless is purely attention bait
This post looks at how to keep Digg visitors. It could be said about Digg that it is a) a timely democratic news source or b) little more than a vacuous popularity contest lacking in substance.
Not that I’m saying that, of course.
“A lot of people consider digg traffic as being useless because they think most digg visitors will never come back to your blog. This is not necessarily true, especially if you do a few tweaks to your blog so you can actually get some benefit from the traffic. These tweaks will not only help you retain visitors from digg, but also will help retain regular visitors as well“