Have you ever noticed online ads seem to be targeted directly at you like you’re in a science fiction movie where the companies get inside your head and magically know what you’d like to buy?

Many of us don’t realize that with every box we check and choice we make online we are telling advertisers what to sell us.  They don’t have to get inside our heads to know what we are interested in buying because we volunteer that information without even knowing it.

Privacy advocates, like the group Consumer Watchdog, are concerned about this use of personal information and suggest companies shouldn’t use your personal information to make a profit.

In 2009, the Interactive Advertising Bureau reported that 80 percent of online advertisements use the targeted systems.

For example, Facebook uses software to track and target your interests, activities and the things you “like” to determine what ads are shown at the side bar.  If one of your listed interests is animals, you may see an advertisement suggesting you support the World Wildlife Fund.  The software will use every piece of information you give including your location, sexuality and relationship status.

Other websites, like Google and Yahoo, target your search history and keywords in your e-mail to determine which ads to show you. Hulu, a media streaming website, uses your viewing history to recommend shows they think you will want to watch.

However, they are only using information you provide, so it cannot be considered an invasion of privacy.

“That’s information you choose to give out,” said 22-year-old senior marketing major Nancy Cauich. “You choose to say that, so it’s kind of like you set the limits, so if you don’t want to say something that’s private, then just don’t say it and it’s not going to be out there.”

But what if you don’t have to say anything at all?

The Wall Street Journal reported last year that in Tokyo, Japan there are billboards that scan you and determine your age and gender to decide which drinks to sell to you.

This may sound like it is all going too far but without advertising all sorts of media would cost more. Newspapers, television shows and websites are cheap or free because of revenue generated by advertisements.

Personally, I enjoy targeted online ads. I have listed on my Facebook page that I am interested in running and writing, so I was targeted with an ad from Nike when a job position opened for someone to write a running blog.  I also “like” adventures and live in Los Angeles, so Facebook knew to target me for an adventure race in Southern California that I wouldn’t have otherwise heard about.

Actor Will Rogers famously said, “Advertising is the art of convincing people to spend money they don’t have on something they don’t need.”  There may be some truth to this but I think consumers are smart enough to determine if they need something.

If people have any willpower at all, they can get through a Pepsi ad without rushing to the nearest vending machine.