You don't have to consider tweets/marketing videos or ads, but a company can get caught out by some things they say, specific items, specific dates/prices etc
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In some cases, an advertisement may become a unilateral contract. If a company specifies a certain number of items available and includes words of promise in an advertisement, it may have the legal force of a unilateral contract. For example, if a company's advertisement states that it only has 10 televisions for sale and states that it will sell the televisions on a 'first come, first served' basis, the first 10 people to respond may require the company to sell the televisions."