Already have good answers, but here's me over explaining all the details just in case:
Creators can unlock the Support Program when they reach 250 subscribers. The Support Program allows tapas users to tip creators with what the site calls "ink". Ink can also be used to unlock premium series. Ink is essentially just what the site uses as currency, and tapas users can buy ink or earn it by watching ads. Ink is just a cute name for money, so when you give, say, 1000 ink to a creator, that is something like $1 in the creators account. When creators reach a threshold of $25 in their account (includes ad revenue) they can have it sent to their bank.
Ink events like InksGiving and Sprinksgiving are ways the site promotes the idea of tipping creators and generally getting everyone in the giving spirit. Typically there is a goal for the total ink tipped by everyone on the site, and if we reach X goal we will get 10% of the ink we tipped back to us, and if we read Y goal we get 30% back, etc. Basically save up your ink for an event, then tip like crazy, so you'll get "cash back" to tip without having to watch ads or spend more of your own money!
If you want to participate in the even but don't have 250 subs this is a rare chance to e-mail michealson and get tipping unlocked early!
Support = Creators can be tipped
Giving Ink = Tipping
Ink = money