Where there is doubt, acceptance to an offer may be by either a promise to perform what the offeror requested, or by actual performance. A makes an offer to B. B can either accept by promptly promising he will do it, OR by performing the act as requested. Some circumstances make it impossible for an offeree to accept the offer with a promise, in which case, the acceptance of the offer is limited to performance only. There is nothing in it for A until B, or someone else, actually performs and finds the dog. A makes B an offer.
B does nothing but give A the silent treatment.
B enjoys the benefits of A s offer and doesn t pay even though B knows darn well that A expects to be compensated. If B, the offeree, does any act inconsistent with A s ownership B is stuck with the offer and its terms unless they are ridiculous. This is the example we talked about with the offer to sell the book, the person keeping the book, not paying for the book, but ruining it, giving it to someone else as a gift, etc.