The syndicates take the strip and sell it to newspapers and split the income with the cartoonists. Syndicates are essentially agents. Now, can you imagine a novelist giving his literary agent the ownership of his characters and all reprint, television, and movie rights before the agent takes the manuscript to a publisher? Obviously, an author would have to be a raving lunatic to agree to such a deal, but virtually every cartoonist does exactly that when a syndicate demands ownership before agreeing to sell the strip to newspapers.
Bill WattersonHobbes: Jump! Jump! Jump! I win! Calvin: You win? Aaugghh! You won last time! I hate it when you win! Aarrggh! Mff! Gnnk! I hate this game! I hate the whole world! Aghhh! What a stupid game! You must have cheated! You must have used some sneaky, underhanded mindmeld to make me lose! I hate you! I didn't want to play this idiotic game in the first place! I knew you'd cheat! I knew you'd win! Oh! Oh! Aarg! [Calvin runs in circles around Hobbes screaming "Aaaaaaaaaaaa", then falls over.] Hobbes: Look, it's just a game. Calvin: I know! You should see me when I lose in real life!
Bill Watterson