What are the four elements of a valid contract?

Describe the objective theory of contracts. How does that theory apply to this case?

Why do you think the court held that there was not a valid agreement here?

Are advertisements generally considered offers? Why or why not?

How does this case differ from a reward situation, where a unilateral contract is formed upon completion of the requested act?

Reference: Seattle man loses in battle with Pepsi for Harrier-jet prize. (1999, August). Wall Street Journal.