Link listing to ALL similar listings in inventory at setup, whether on or off market at the time. Every time you enter a new listing, select the similar listings to guide prospects to. But keep this link so that you don’t need to set up again each time it goes on the market. Also when prospects click on a link to a property off the market, they will always be directed to all the similar listings you have that are on the market without having to select them each time. I sometimes leave old ads up to drive traffic to similar listings. I did this today and found that because one listing went off market before another was posted, when I posted the new listing it did not link to the old listing. Visitors to the old ad were not recommended to the new listing.