Tithing

From CaseyPedia

Tithing is the practice of Christians giving 10% of their income to their church, as commanded by Jesus Christ. In Casey Serin's case, considering that his yearly income is strictly negative, he has requested that the church pay him 10% of their collective income. This is his rationale for including "tithing" in his cash flow charts.

Unfortunately, because Casey is an ideas guy and not a details guy, he does not appear to have got round to collecting any of this money, though according to the rationale above it must now amount to a substantial sum.