Unusual Word Time! The exact definition of a "tithe" is a bit complicated, but it usually means a portion of income or wealth (usually a tenth) given to a higher power. I've also heard it used in reference to the fae and other supernatural creatures; namely, give them stuff, and they'll go away and leave you in peace, which is more or less what's happening here.
Oh Jareth, you're such a bully. Note how, despite Erik's apoplexy, Jareth does not look the least bit concerned.
Also! The question of who's who in Oz is finally answered. (Though Norrington won the vote by a landslide. Hm. May have to do extra fan art...)
Erik belongs to Leroux and Webber.
Jareth belongs to Henson, Lucas, and Bowie.
Norrington belongs to Disney, Bruckheimer, and Davenport.
Javert belongs to Hugo, Boublil, Schonberg, and Kretzmer.
Oz and associated material belongs to Baum, Arlen, and Harburg.