If you want to entice a mouse to follow you out of your house - you provide a trail of yummy bread crumbs calculating that her needs (hunger) will cause her to follow the crumbs out of the house. Bread crumb marketing takes that practice and applies it to the potential customer. Create a series of bread crumbs for your potential customer to follow and they should follow you to where you want them - to your product or service.
So, you should be focused on inspiring your potential renter to take small steps (following the bread crumbs), ultimately resulting in the signing of a lease for your apartment unit and moving into your building. So, where do you start?
First, the potential renter sees your ad. But what will seeing that ad cause the potential renter to do? You have to get them to click on your ad to see your pictures. The photos and copy have to be so good, that the potential renter wants to go see your available apartment. They have to call you on the telephone and you may have to call them back. An appointment must be made. That appointment must be kept. She has to be able to find your unit and find a way to get there. She may have to park. Once you get her through the door and into the unit, you then have to sell that unit. You must create some sense of urgency to act so she will apply for the apartment. But even after she applies, you still have to get her to sign the lease.
No one goes from noticing an apartment is available to signing a lease and moving in. Tarket your marketing in line with the small steps the potential renter must go through.