Marketing a blog depends on the owner if he/she posted a number of posts. It doesn't matter to me if I already posted just a single article or even 10. With 10 posts, its positive effect is there are various of articles already to choose from. If an audience, liked two or three posts, he/she will keep coming back, depending on what kind of articles you have posted.
It's not also a problem if you only posted one article. From time to time, you can pick-up more audience through effective marketing.