Joel: more than likely, your realtor has a distribution network that will automatically distribute your listing to various on-line outlets. amazingly, however, this process is not instantaneous, and it can take 24-72 hours for various outlets to pick up and properly display new listings or changes to existing listings. What most people do not realize, is that not all realtors are created equal in this area, and nor are all real estate firms. Some firms have relationships with additional outlets that are not part of whatever constitutes "basic" marketing these days -- perhaps realtor.com, trulia.com, and zillow.com. Since your ability to sell your home is all about your realtor's ability to effectively market your home, i'd recommend an in-depth conversation with your realtor on this point. Then, the other thing you're going to want to look for are individual realtors who have enhanced placement (i.e. your listings at the top of the list) on the various outlet. On Trulia, that means you want a Trulia Elite Pro realtor, on Zillow it's called Premier. The best way to figure out whether your realtor is what you are looking for is to get on those sites and see whose listings are appearing at the top of relevant searches. Pretend you are looking for your own home, and see what you find. That will tell you a lot about who might be more effective than others when it comes to on-line visibility and distribution.