The following is the statement Samsung has issued:
However, because our customers’ safety is an absolute priority at Samsung, we have stopped sales of the Galaxy Note7. (Source)
I am wondering why "at" is used in this case instead of "in" or "of". My basic idea about the preposition "at" is that it is more used when meaning physical places. For example, "I bought this at a store." So, if I wrote this, I would say "a priority of Samsung" or "a priority in Samsung." Are those prepositions interchangeable in this case? Or any differences between those?