08/06/2011 02:54 pm ET Updated Oct 06, 2011

Twitter MVPs: Pop Princesses Top Klout's 'Most Influential Actresses' List

Forbes ranks the highest paid actors and PEOPLE has its “Most Beautiful” issue, but lately the lists with the most gravitas in Hollywood tell us who has the most influence online.

Is it the big players like Angelina, Reese, Julia? Not one bit. Those ladies are too busy counting their cash and well, working, to tweet. It shouldn’t come as a surprise that young Hollywood, particularly Disney’s pop princesses are by far the most popular actresses on the Internet.

This week Klout.com released its list of the top 10 actresses ranked by their Klout score, which is a measure of how much people pay attention to someone online. The popularity poll tells us that the top five most influential actresses in social media are none other than Demi Lovato (Klout Score: 94), Selena Gomez (92), Ariana Grande (90), Miley Cyrus (89) and Bella Thorne (87).

Average age of these influential tweeters? Seventeen.

This means these five young women have the most influence over their networks -- meaning they tell them what to watch, what to listen to and what to buy.

So what exactly is a Klout score? The Klout weighs 25 variables, including the size of the social sphere -- such as the number of followers -- and the number of engaged followers and friends versus the number of spambots and dead accounts, to determine how much online influence a person has. Re-tweets and mentions are also taken into account, so it isn’t just how cool you are, but how cool your network is perceived to be. It is lunchroom politics boiled down to an algorithm.

There area few noticeable tweeters missing from Klout’s list, but just note that the three Kardashian sisters were excluded from the list because, well, they don’t act.

Klout may tell us who gets followers to do things, but there is another social media measurement that tells us who directly gets us to buy things. We had the folks over at Ad.ly, the company that pays celebrities to tweet on behalf of brands, compile a second list of their paid Tweeters to help us firgure out who is influential when it comes to getting consumers to click on things online.

Who is Ad.ly’s biggest actress influencer? This one’s a shocker.

Lindsay Lohan.

Her branded tweets are clicked on 3.5 times more than the average celebrity in the Ad.ly network.

“While we don't disclose specifically what that Ad.ly celebrity average is, it is in the thousands. Lindsay is up there in the Mt. Rushmore of actresses on Twitter,” Ad.ly VP of Marketing Krista Thomas told The Huffington Post.

Lohan might not be able to sell a movie too easily these days, but she can get you to buys things she is paid to plug on Twitter.

Other top Ad.ly celebs? They might surprise you.

Though she’s been off the radar for awhile, Eliza Dushku’s tweets are clicked on 2.6 times the average and former “90210” star Tori Spelling’s tweets are clicked 2.5 times the average. Add the Kardashians into this mix and they are clicked on 3.4, 3.3 and 2.4 (Kim, Kourtney and Khloe, respectively) times the average Ad.ly celebrity.

It certainly doesn't look like the celebrity Twitter phase will go away anytime soon, but that doesn't mean every actress, reality star or singer has something important to say. Check out the slideshow below to see some of Twitter's worst celebrity tweeters.