Placing your customer’s interests before your own is not self-sacrificial.
Actually, it’s the most profitable way to do business.
After all, nobody’s going to buy from you because you have a quota to meet, or because you need the money, or even just because you are a really nice person.
They’re going to buy from you only because they believe that they will be better off by doing so than by not doing so. In other words, that they will benefit.
So if you want to dramatically increase the chances of a sale taking place…then focus on their needs — not yours.