Over the weekend, Katy Perry became the first celebrity to roar past the 50 million mark. That means that Perry has 50 million followers, or Katycats as she calls them, on the social network. Being the cool kitten she is, Perry took hitting the landmark in stride, tweeting on Saturday:

We, however, were wondering what it is about "Firework" singer that makes her such a hot draw on Twitter? We did a little research and came up with 10 reasons why Perry is so Twitter-tastic.

1. She's easy on the eyes. Sure, Twitter isn't Instagram, but occasionally Perry posts photos on Twitter, like the one of her and her brother on the way to the Grammys late last month.

Or, the one of her and her boyfriend John Mayer on a mechanical bull, taken from the shoot for his video of their duet "Who You Love."

2. She's John Mayer's girlfriend. Since Perry is hanging out with her famous beau, you're likely to get double the fun and double the celebrity news about one of pop music's most beloved couples. Mayer has been on a Twitter hiatus, but now he's back in the game, as Perry noted on Jan. 31 when she tweeted:

3. She's just like you and me. Despite the fact that Perry is incredibly hot, incredibly famous and incredibly talented, she's not all that different than common folk -- at least if you judge her by her tweets.

[Related: Vin Diesel Is So Psyched He's Dancing to Beyoncé and Katy Perry]

4. She has famous friends (aside from Mayer). Just the other day, Perry sent a tweet of thanks out to her pal Madonna.

5. She has a sense of humor. While some stars might be offended by ridiculous photoshopped pictures, Perry is not. In fact, when the Twitter account Pharrell's Hat tweeted a pic of Perry and Taylor Swift "wearing" Pharrell's Dudley Doright-style hat on the Grammy red carpet, Perry re-tweeted it to her followers.

6. She's humble. When her latest single, "Dark Horse," jumped to the top of the Hot 100, she sent out the following tweet:

7. She's philanthropic. Perry's not just pimping tickets to her latest tour, she's also letting fans know about special seats with the proceeds designated for charity.

[Rleated: Chart Watch: Katy Perry Ties Rihanna's Record]

8. She promotes new artists in different genres and their fashion statements.

9. She has a social conscience. She might not have the answers, but at least she's bringing up some of society's problems for her Twitter followers to mull over.

10. She gives props to her biggest fans and their fan-made videos.

Follow me on Twitter.