Look, we all like to laugh at an awkward crossover. Fraiser shows up on Star Trek! Yosemite Sam fights Jonah Hex! But the thing is, you can use those as a roadmap to construct an elaborate shared universe. And if you connect all those dots, you can logically prove that, for example, Batman and Papa Smurf probably bump into each other in line at the deli all the time.
Don't believe us? Allow us to demonstrate.