Final answer:
Revocation is usually effective when it is received by the offeree in most states.
Step-by-step explanation:
In most states, the revocation of an offer is usually effective when it is received by the offeree. This means that the offeree must actually become aware of the revocation for it to take effect. A revocation sent by the offeror may not be effective if it is not received by the offeree in a timely manner.