It's wise to write articles on topics which has very high demand online.But while doing this you should keep in mind that the subject of the article should match the topics of your blogposts.For example,if your blog is on money making tips,you mustn't write about celebrities there to attract traffic.This will destroy the reputation of your blog & the visitors will not come again to your blog.
This is a great idea! thanks for sharing it. Although on a personal site, it wouldn't matter much does it? But I agree, if you're a business blogger, better stick to your business!