Get It In Writing
Whether a buyer or a seller, when buying or selling a home, always rely on the written sales contract which is a promise to perform. if it isn't written in the contract, then don't be surprised if the other party doesn't keep their verbal promise.
This is mostly an issue on the buyer side. Let's say a buyer is negotiating the purchase of a home and ask for something in particular in the offer. The seller says yes we'll do it, but let's not put it in the contract. Even though there is a very high likelihood that they'll keep their word, red flags would be popping up like daisies in springtime.
Of course, as a Realtor® it's only my job to advise my client not to commit to anything that the other party is not willing to put in writing. Intentions may be good, but you just never know what could happen. Murphy's Law is ever present.
Imagine that one of the parties reneges on the verbal promise and that the reneging party relies on the written contract to make his case and the written contract is absent of the verbal terms of the agreement. The party that has the most to lose, will likely lose if arbitration becomes necessary.
When buying or selling a home, it's important that agents remember that they have an obligation to represent their client to the best of their ability. Their responsibility is not to stay in the good graces of the listing agent over the best interest of their client. Whether a client accepts or rejects your advice to always get it in writing, best practices dictate that you give them sound advice and you can never go wrong when advising to get something it in writing.