When writing content for your website, the more topical you make the articles that you write, the more traffic you’ll receive and thus the more links you’ll attract, which will help your rankings.
For example, if a celebrity dies, gets married or does something newsworthy they’ll receive a lot of online coverage on various websites. They’ll be talked about on Twitter, blogs and social networking websites and people will be searching for them in Google and other sites. Therefore, if you write about them you’ll receive traffic for those searches.
Now, this doesn’t mean you have to write irrelevant content about celebrities just to gain traffic for searches based on their name. You can always work the relevance into your article with some clever writing.
Say for example you wanted to write about Britney Spears, but didn’t want to simply write an irrelevant article about her as it wouldn’t fit your website about car bulbs. You could write the Britney Spears guide to changing car bulbs, in a funny tone and made simple so that even Britney herself could understand it. This way you’re writing something relevant, yet topical.