13. What makes a successful campaign?

Once again, people. They have to click together; it’s no reflection on anyone but just because two people are friends with you, they won’t necessarily be friends with each other. We’ve had good luck in this respect, but sometimes you hit on incompatibilities even between people you all dearly love.
And of course they have to share enough interest, hopefully enthusiastic, in the setting, genre, characters, and plots.
In terms of logistics, availability and reliability. Classic gamer problem: every one wants to play but no one is available at the same times! Gaming is also a different priority for different people; for some, they really enjoy it but if they get an offer for some activity they enjoy they will cancel right at the last minute. Others expect the GM to call and remind them every game, no matter how firm the schedule arrangements were.