Two reasons to cancel open house if an offer gets accepted that day (which locks the seller to this buyer):

1) Buyer’s remorse sets in immediately, so it keeps the buyers happier because I’m committing to them and they don’t feel like I’m shopping their deal around, and

2) Keeps open house attendees from resenting the tease of seeing the house but not being able to buy it.

It is sensitive, and I can see why many agents go ahead with their open houses in order to get more leads and potentially a backup offer – but they risk tipping over the buyers. We already saw how easy the last buyers cancelled, so I don’t want to shoot myself in the foot.