[brentb]

The problem is you're not "simply mentioning Hacker News in the post title", you're running an experiment about the effects of mentioning Hacker News in the title. Unfortunately, your experiment has a few flaws.

First of all, others might upvote this post simply because they're intrigued by the experiment itself (or for any number of other reasons) and not because of what is or isn't in the title. Secondly, your sample size is one and there is no control group (that I know of).

If you're truly interested in studying this, might I suggest reviewing historical hacker news submissions and, after controlling for as many other effects as you can (author reputation, time of day, other keywords in title, etc.), measure the statistical impact of having the words "Hacker News" in a title. It might be a bit of work to gather, parse and analyze the data you need, but I'm sure the community would be interested.