Most Realtors know that the most active time in a listing is the first 3 weeks. This is because the listing goes in front of all the Realtors and customers who have automatic searches set up. All the social media advertising has it at the top in the beginning of the listing as well. If the house is priced properly in this stage of the listing it will sell.
After a couple of weeks, the activity starts to slow because all of the potential buyers have already considered the listing and decided it was not for them or did not see the value compared to other competing listings and bought something else. The only thing at this stage a seller and their Realtor can do to bring it in front of all the potential buyers again is reduce the price.
Studies have shown that listings that are priced well in the beginning sell for closer to list price and sell in less time than a house that has been reduced in price. The message is that good marketing only works with the right price.