I disagree that it’s legal to break their promise about the $1000.
First, writing a letter is giving value. Most people aren’t very good/fast/experienced writers. It could take them over an hour of high effort to write a letter. A perfectionist might take over ten hours. I don’t think you can offer money in return for a lot of work, then back out after lots of people do the work.
Second, the employees also give value by doing work for the company. They could reasonably have interpreted the $1000 as a perk they’re getting as part of their employment, not an unrelated, arbitrary perk. Employment was a condition of getting the perk, which makes it seem like it’s in return for being an employee, not in return for nothing. It’s common to give perks to employees to raise morale, to get away with lower wages, to get tax breaks, so you can brag about those perks to people you might hire, and for other reasons. I think those perks are and should be legally binding, once offered, even if employees aren’t required to do any extra work to get the perks. (How to cancel/change perks is another topic, which I think is often handled poorly, but anyway just cancelling it after a few days and never paying anyone isn’t reasonable; saying there are lots of letters so the offer now expires in a month sounds much more reasonable.)
Third, companies sometimes do giveaways/contests for customers. They can’t back out because too many customers take them up on the offer. I think companies should be (and generally are) held to a higher standard for how they treat their employees than for how they treat customers. Employees can reasonably expect to be treated at least as well as customers, not screwed over when customers would not be screwed in a similar situation. One reason is the employees are providing a lot more value to the company than the customers are. Another is the company is in a much better position to abuse/mistreat/exploit/harm the employees than the customers (it has more power and control over them). Also, those contests often have a “no purchase necessary” clause, and I think they’re still binding anyway – the company can’t say “well you didn’t give us anything, so we can back out”.
Also, in general, contracts are enforced much more strongly and literally on sophisticated parties like big companies with teams of lawyers. They get way fewer opportunities to get out of it. That makes sense. If an poorly educated laborer signs an exploitative contract that he didn’t understand, where he has to give a big company $1000 for basically nothing, then it often makes sense for courts to overrule that contract. The company’s lawyers tricked him (it often involves some kind of misrepresenting the contract and therefore fraud, btw). But it generally wouldn’t make sense for courts to protect the big company from the laborer. The company had highly paid executives and lawyers who knew what they were doing (or should have) before making an offer. Pleading incompetence and not understanding the contract, and it being too one-sided against you, doesn’t make a lot of sense when you wrote the contract on your own initiative and had your lawyers and highly-trained/educated company leaders look it over. Similarly, when two big, sophisticated companies do business with each other, they expect the other company to keep to its word and take responsibility for what it says, since they have the budget and expertise to do that. Laymen can make excuses about unfair contracts and being taken advantage of, but big companies generally shouldn’t be able to make those excuses.
BTW, I see a lot of posts on r/antiwork where a company made a clear offer then broke their word, including about really important stuff like how many dollars per hour someone would be paid. And the attitude in replies is often basically “if they didn’t put it in writing, there’s nothing you can do”. I don’t know how true that is in practice, but verbal contracts often should be binding! But commenters are often very aggressive about recommending complaining to HR, complaining to the government or lawsuits whenever there’s a paper trail, and are like “learn your lesson and get a paper trail next time” when there isn’t, and I find it kind of strange how much they think paper trails matter because in principle it makes little difference whether an offer was in writing. I don’t think the communication medium used for a contract is a primary issue. I also don’t think lying about what you verbally promised an employee is easy to get away with if anyone questions you and you have to keep your story straight, and you also have to make sure no one else overheard the conversation and there were no cameras recording. And people often don’t want to lie, or want to limit how egregious their lies are, because they have some morals and/or care about their reputation and/or don’t know if the employee recorded the conversation on his phone (or has saved texts/notes/tiktoks/etc documenting what was said which will make his story more credible).
BTW, here’s an example of a documentary about a big company (Pepsi) trying to get out of providing a contest prize (a jet) advertised to the public. I won’t spoil what happened here but I have some opinions I might share if anyone watches and discusses it.
Here’s another example of companies acting badly for someone to analyze:
