"I'm not as good of an Instagrammer (sic) because I'm like, 'Why should I rule both Instagram and Twitter, let someone else rule...' I'm super nice." Pop star Katy Perry jokes about her status as the most popular person on Twitter.com - a title she claimed last month (Nov13) after overtaking Justin Bieber with 46.51 million followers. On Friday (20Dec13), it was revealed that she has retained the title for the end of the year (13) with 48.6 million followers to date.