Stack Overflow devotees write responses in anticipation of rewards of the tribe. Each time a user submits an answer, other members have the opportunity to vote the response up or down. The best responses percolate upward, accumulating points for their authors (figure 19). When they reach certain point levels, members earn badges, which confer special status and privileges. Naturally, the process of accumulating upvotes is highly variable—no one knows how many will be received from the community when responding to a question.
