Sellers often find it useful to sell products without revealing the terms of the contract to buyers until after buyers have taken the products home or begun to use them. These transactions take a number of forms. A buyer might purchase a box containing software or a database from a store. The box’s skin bears the name of the software and a description of its function, and perhaps a statement that other terms are inside, or perhaps not. The buyer learns the terms only after he takes the box home and opens it; if he does not like the terms, he can return the product as long as he has not yet begun to use it, and sometimes not even then. A buyer might order a computer or appliance or airplane ticket over the phone. The operator tells him none of the terms other than price and a few others; again, he learns those terms when the product or ticket arrives and may (or may not) have an opportunity at that point to repudiate the transaction.