Does Streeteasy Caputre Most Open Houses

My primary source for listings is my broker database, but I also check Streeteasy and the NY Times, and I find that they are all remarkably in synch - the main difference between the three is that the Times carries FSBO listings, as well. In cases where a broker listing doesn't show up (whether an Open House, or not), I'd chalk it off to a timing issue. There's a synchronization that takes place between Streeteasy, the Times, the broker websites, etc. - so not all will reflect the exact same information at the same time. The fact that OH's are often scheduled on short notice is probably the main reason you might see an OH on the broker site but not elsewhere.

I think the OH's you might miss would be minimal. And going through all the broker websites to compare against Streeteasy sounds like a full time job.