Your rank is displayed in your profile on the upper right, but what does this number mean?
Right now your rank is based solely on your bankroll. The higher your bankroll, the better your rank will be. Since rank is based only on bankroll, it is influenced by chip purchases.
For ranking, a lower number is better. The highest rank is #1, being the player with the biggest bankroll on the site. Each player after that has a smaller bankroll than the player before.
Rankings update every 15 minutes. Chips in-play are NOT counted in your bankroll. Once you leave the table and your chips are returned to your bankroll, your ranking will reflect this change after the next update.