Q: Our website averages about 5,000 hits per day. Then one day a few months ago it inexplicably jumped to around 15,000 hits, but it was just for that one day. They dropped right back down the next day. I was wondering, what could cause this? We didn’t have any special events or press releases that day. Nothing out of the ordinary happened in our company. Any ideas?

A: There are various reasons that traffic on a site can spike in the way you’ve described. As you mention, you would often expect to see that type of behavior when there is an unusual event, press release, or other online promotion that might cause more visitors to come to the site. These days, a sudden, short-lived increase in traffic might be a result of getting some notice on a social networking system such as digg, reddit or del.icio.us.

Another, less delightful possibility is that the site was repeatedly hit by some sort of robot. This could be a search engine robot or an undesirable visitor such as a scraper bot (bots that are coming to the site to steal its content) or other spam manifestation. And if the site is dynamic, sometimes it is possible for a bot to get into an infinite loop and bounce around the website for a while, which could throw off your statistics.

Your best bet at finding the answer to this mystery will be checking your log files or website analytics program. I would start by checking referrers on the day in question – this is a quick way to see if there’s a link in some prominent website that you were unaware of. If this doesn’t answer your question, then you might want to review the part of your stats where it tells you what type of browsers or spiders (usually called User-agents in analytics programs) were visiting. Look for unusually high numbers from certain user agents or any other striking activities here.

And the big take-away from all of this is that “hits” is often not the most meaningful metric for a website! You might want to use this experience to choose some more helpful key performance indicators, such as sales or leads.