"Your offer will be purely merit-based"

what's that supposed to mean?Thank you in advance~!
Sounds like part of a job or salary bonus offer. It means that the salary and benefits they offer will depend on merit - i.e. how much experience you have, how well qualified you are, or how well you have performed. It means that there is no set amount, it will vary from person to person.
I can think of another case...

When a student applies for a scholarship to attend college, he may qualify either for a merit-based or need-based scholarship. Merit-based would be based on your grades, SAT/ACT and extracurricular activities whereas need-based would depend on your financial situation.

So if a scholarship is purely merit-based, it means they don't care how rich or poor you or your parents are. It is strictly based on your academic merit.
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I see,Thank you!
 Danyoo's reply was promoted to an answer.
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Thank you ,Danyoo,

I think ,from you said ,"The offer is purely merit-based. " meant "the offer is given according to each student's academic performance".