Illustrations:
例释：
5. In consideration of one cent received, A promises to pay $600 in three yearly installments of $200 each. The one cent is merely nominal and is not consideration for A''s promise.
5.考虑到接受的1美分，A允诺将以每次200美元的三年分期付款方式支付600美元。这1美分仅仅是名义上的而非A允诺的约因。
6. A dies leaving no assets and owing $4000 to the B bank. C, A''s widow, promises to pay the debt, and B promises to make no claim against A''s estate. Without some further showing, B''s promise is a mere formality and is not consideration for C''s promise.
6.A在临终时未留下任何遗产并且还欠B银行4,000美元。C作为A的遗孀允诺为A还债，B也允诺不对A的不动产提出请求。在没有进一步表示时，B的允诺仅仅是一种形式而非C的允诺的约因。
e. Effects of gross inadequacy. Although the requirement of consideration may be met despite a great difference in the values exchanged, gross inadequacy of consideration may be relevant in the application of other rules. Inadequacy "such as shocks the conscience" is often said to be a "badge of fraud," justifying a denial of specific performance. See § 364(1)(c). Inadequacy may also help to justify rescission or cancellation on the ground of lack of capacity (see §§ 15, 16), mistake, misrepresentation, duress or undue influence (see Chapters 6 and 7). Unequal bargains are also limited by the statutory law of usury, by regulation of the rates of public utilities and some other enterprises, and by special rules developed for the sale of an expectation of inheritance, for contractual penalties and forfeitures (see §§ 229, 356), and for agreements between secured lender and borrower (see Restatement of Security § 55, Uniform Commercial Code § 9-501).
e.重大不充分的效果。虽然在交换的价值存在巨大差异的情况下约因的要件可能得以满足，但是约因的重大不充分可能与其他规则的适用相关。“诸如撼动良知”的“不充分”经常被认为是“欺诈的徽章”，这就使得对契约义务的具体履行得以正当化。参见第364(1)(c).不充分也可能有助于因能力欠缺（参见第15，16条）、错误、误述、胁迫或者不正当影响（参见第6章和第7章）而导致的无效或者撤销得以正当化。不平等的协商也受到暴利法的限制以及公共设施和其他企业费用的规制，以及为继承预期买卖、契约处罚和罚款（参见第229条，第356条）、有担保的出借人和借用人之间的协议（参见
担保法重述第
55条，统一商法典第9-501条）而发展的特殊规则的规制。
