These days, it seems like everyone is on Facebook. Most people you know probably have a presence on the site, and now there are numbers to back that up. According to a new study by Edison Research, more than half of Americans have profiles on the social-networking site.

Don't be surprised if you get a friend request from your grandmother. Fifty-one percent of Americans ages 12 and up have Facebook accounts says Edison Research, which will release a full report on its findings in a webinar on April 5. This is Edison's 19th study on digital media-related topics. Edison has been tracking the growth of Facebook since 2008 and says the site was only used by eight percent of Americans of the same age just three years ago.

According to Facebook's official numbers, there are more than 500 million people on the site worldwide. That's about the same as the combined population of the European Union. Since 2008, Facebook usage has increased a lot, especially among people 35-years-old and up, the study says. Edison Research polled 2,020 people ages 12 and up to come to these conclusion. However, the findings are interesting, considering the sample size is relatively small and minimum age to even have a profile on Facebook is 13.

Facebook says it enforces that rule, too. In fact, last week Facebook said it removes roughly 20,000 profiles each day, many of which belong to underage users.

However, there are a number of other reasons that account for the number of profile removals, including spam and inappropriate content.

Facebook did not immediately respond to a request for comment on the findings.