15.1

a. The BLS Web site at 3 in the morning has the capacity to serve far more users than it attracts, so an additional user calling up the site does not prevent some other user from doing so. Other Web sites, however, do not show the nonrival property, at least during certain hours, because they attract more users than their servers can accommodate. LO1

b. The stadium at the championship game is always full, so anyone who watches the game in person prevents someone else from doing so.

c. Additional people can watch the game on television without diminishing the availability of the telecast for others.