Shopping online is usually convenient, easy, and a way to save money. But Consumer Watchdog of Santa Monica says if you're shopping online through Google, it might actually be costing you money. Consumer Watchdog did a test comparing prices of several popular items, such as digital cameras, toasters, iPads and electric drills using Google Shopping. They found the difference in price could be as much as 67 percent.

"It's happening because Google is a monopoly. They're able to control what they display. They feature their own results and push the other sort of shopping engines that would maybe give competitive information out of the picture," said John Simpson with Consumer Watchdog.

Consumer Watchdog says that most of Google's ads are clearly marked. But there are some images to the side that are ads too. When you click on one of the images, it takes you directly to a merchant, giving you the impression that you are getting the item for the lowest price. But Consumer Watchdog says that's probably not the case.

"The merchants pay more to get in the premier location. Those prices, because they're paying more to bid to get in there, means that consumers are paying more because the merchants are raising their prices," said Simpson.

Eyewitness News contacted a Google spokesperson, who said they have no comment. Google Shopping has been around for 18 months and displays the word "sponsored" next to the products. If you shop online, make sure that you shop around online. In other words, take the time to do your own comparison shopping for the best price.