I was browsing around News.com yesterday looking for my fix of tech news and I noticed something: an ad.

I know. Many people have display advertising blindness but unfortunately I still notice them from time to time. This one stood out, however. It’s the ad you see to your right.

The reason? It was advertising United States President Barack Obama’s upcoming appearance on CBS’ 60 Minutes. Days after it happened.

This isn’t the first time I’ve noticed an obviously out-of-date ad being displayed. It happens. But it serves as a good example of something that happens all too often amongst marketers large and small: we don’t stay on top of our campaigns.

In this case, since News.com is owned by CNet and CNet is owned by CBS, there probably wasn’t any ‘real‘ money being wasted. But what was wasted: opportunity. Obviously, showing an ad for an event that already took place probably isn’t going to be effective and it takes up a spot that could have been filled with an ad that had the chance to produce something worthwhile.

Every ad that is displayed is an opportunity to reach a consumer. An opportunity to influence a consumer. An opportunity to spark interest. An opportunity to earn a sale.

When campaigns are not managed properly, things slip and mistakes are made. Advertisers lose because they’re not taking advantage of the opportunity the ad presents. Publishers lose because the value of their inventory is maximized when the advertising is relevant.

The waste from the kind of laziness evident on the News.com has a dollar cost and an opportunity cost. Both of those are expensive, especially at a time when ROI has never been more important.

If you’re running any ad campaigns online, be they display ad campaigns or PPC campaigns, don’t make the same mistake. Remember to stay on top of your game because in today’s ad game, when you slip, you lose.