An exclusivity clause stops you working with competing brands for a set time, so it has real cost to you and should be paid for. Sign it only when three things are true: the category is narrow, the window is short, and the fee covers the deals you are turning away. Broad exclusivity that blocks a whole industry for a year on a single post fee is a no. Narrow exclusivity, like one snack brand for 30 days with a premium on top, is often fine.
What you are giving up
Exclusivity rents your right to earn elsewhere. Price it like lost income.
Know the types
Category exclusivity blocks rivals. Total exclusivity blocks everyone. The second costs far more.
Check the window and scope
One month in one narrow category is reasonable. A year across an industry is not.
Negotiate before you sign
Shorten the term, narrow the category, add a fee. Most brands expect the ask.