The phrase "proverbial nail" refers to something that is commonly known or often talked about. It is usually used to emphasize that something is well-known or frequently mentioned, like a common saying or popular idea. Full definition
MTV hit the proverbial nail on the head when they gave the Best Villain award to Lucy Liu for her role as O - ren Ishii, the Japanese / Chinese / American crime boss in the first installment of «Kill Bill.» (bullzeye.com)
By directly tying their business goal with a reward that users highly value (additional storage space), the company has hit the proverbial nail on its head, and sent product adoption rates soaring. (elearningindustry.com)