Needs checking: real brands rarely do it, scammers imitate it
"The offer expires tomorrow": pressure as a sign of a scam
An offer that expires tonight, an answer demanded within 24 hours, "only 3 spots left": pressure stops you from checking. That is its purpose.
What it looks like
Please answer quickly: the offer expires tomorrow and we have other creators waiting.
Why it is a sign
Checking a brand takes ten minutes. The fake deadline is there to take them from you. Consumer protection agencies list pressure to sign fast among the first signs of a fake offer.
What a real brand does
A real campaign has a schedule, and the brand says so: the publication date it hopes for, an answer within the week. It does not put a countdown on you.
What to do
Take the time to check: official website, sender's address, whether the person exists. A serious brand will wait for your answer.