Oh, PEDRO12 gift donated me $5. It was added on to my initial Tier 4 that I got from PCX.
The most common way to get PC Supporter is to donate money to the site using the PayPal link above. It can also be earned by winning certain competitions in Get-Togethers or any other similar event.
There are 5 main tiers, and one secret VIP tier.
PC Supporters get lots of cool features like extra PM space, larger avatars and profile pics, blogs and also more profile customization options (such as custom backgrounds like mine).
More details on PC Supporters can be found here.