I often get emails asking this question, and usually the answer is one of these three reasons:
1) When creating an account on Zillow, it is essential that the agent register as a professional, not a standard user. When we get a listing feed, we match the email address on the listing with the email address on the profile. The reason we wouldn't post this listing online is that a standard user can't represent home that has a listing agent. So if listings aren't online, first make sure it is a professional account that has been created, and not a standard one. This is easily changed on the profile, or click the gray "flag" button and our customer service can assist with the switch.
2) Often when I get this question, the listings actually are online, but they aren't in the My Listings section of the agent's profile. As mentioned in #1, we match the email address of the listing to the email address on the profile. It is important to create the agent profile using the same email address as what the feed provider has on record. For example, say a profile is created using the address email@example.com, but then the franchise is giving us listings using firstname.lastname@example.org. The listings would be on the site, but the listings and profile would not be tied together. Again, this is easily corrected be updating the email address on the profile.
3) Agents often assume that we are getting direct feeds from their MLSs, therefore the listings should be online. The truth is, only a handful of MLSs give us direct feeds. However, a large majority use syndication services on their members' behalf, like ListHub or Point2. Often with these services there is some type of opt-in required by either the agent or broker before the syndication can begin, so make sure the appropriate controls have been set up if you MLS is contracting with such syndication services.