Simple in concept, not so easy in practice: Any property that is for sale, remains for sale until a contract is both accepted and signed by both parties. That's when it is off the market. Let's say that I have had several verbal offers and various indications of great interest from several folks, but if so far no one has signed anything and we don’t have the owner’s signatures. We need both to make it a valid contract and to take it off the market. Verbal offers and the degree of your interest means little, not in a legal sense.
I try to keep folks abreast of developments if I know they are definitely interested in a property. It would be improper for me to play favorites; I have to be fair to all and to also keep the owner's best interests in mind. Someone can always come in out of the blue and make a higher offer, higher even than the asking price, if they are so moved, and everyone else could be left suspended in space, wondering what happened. That is rare, I’ll admit, but I have seen it happen - more than once. Once the Purchase Contract is signed by both parties, that person who came in out of the blue will have to wait and hope that the person who first agreed to buy a property will not be able to perform as stipulated, finally leaving it open to them. That happens too, though it is far from common.
While the price is always paramount to a seller, their conception of a buyer’s ability to perform is also extremely important. I tell sellers that I’d rather see them get a somewhat lower price from someone we know can close the deal than to get theoretically more from another party only to find out weeks later that they could not get the money. Sometimes they listen to this, sometimes they don’t. Real estate is a classic case of capitalism at work.
Because someone is intending to seal a deal does not automatically put them in first place. Suppose you came up and changed your mind at a second look? That happens. You are not obligated to buy just because you think you want to buy it, nor is the seller obligated to sell. to you. No agreements have been made. Nothing is in writing. It's all just talk at this point. I tell sellers not to get excited over a buyer until we see two things: something green in my hand and a name on a dotted line. Then we can start to make plans.