It seems the practice of posting a "Coming Soon" rider on a For Sale sign is increasing in popularity. Zillow has announced that it is going to offer the ability to advertise properties 30 days prior to that property actually being available to purchase.
Approach this new marketing tool very carefully. Ask yourself "Who does this benefit?" The answer might be surprising and not what most sellers would expect.
Consider the normal practice of marketing a property. The first 2 weeks are the most important weeks of a listing - this is the period in which the sellers are most likely to get their listed price. Most Realtors will make every effort to have the sign go up, advertising to be made public and have the property hit the internet at the same time. This makes the biggest impact for the property.
Now, consider the "Coming Soon" approach. The sign goes up and....the buyers are told they cannot see the property and Realtors are told they can't show the property. The sign becomes a fixtue and after a couple of weeks, no one pays attention to it anymore. The property is already "shop worn".
Knowing all of this, why would anyone want to take on this kind of strategy? Who does it benefit? The common phrase "Follow the money" will answer this fairly quickly. Despite other Realtors being told they cannot show the property, the listing agent has no such limit. The listing agent has access to the property and can show the property at will. If the listing agent sells the property, the potential is to double their commission.
One may ask why this would be an issue. Research shows that homes that do not go on the open market sell for a lower price than those that are exposed to the open market...and this difference is substantial. We are already seeing lawsuits from sellers who realized after the fact that their home could have sold for more but were not given that opportunity by their listing agent.
If the seller is well informed of the difference in the approaches and still chooses to go the route of "Coming Soon", then there is no issue. However, Realtors should be very explicit in their explanation of the different types of marketing and the consequences of each.