"When you book a flight online, you can see what the different fares are based on what time of day you leave and how far out you book that flight," Johnsey says.
Likewise, large companies that rent out hundreds of apartments now typically have websites that allow consumers to fiddle with move-in dates and the lease length on various units, coming up with various price offers.
"Consumers might see rates change as frequently as daily," says Janine Steiner Jovanovic, president of YieldStar, a Carrollton, Texas, firm providing the computerized systems used by apartment companies.
Whether you're looking for a rental with a large company that maintains a website or shopping among buildings owned by small landlords, the same principles can lower your monthly rent by up to 10 percent or 15 percent, according to industry executives and observers.
The lease length difference
The 12-month rental lease is the most typical, but there's no reason it can't go longer or shorter. An unconventional length can benefit the landlord, who in return can offer incentives for the renter to go either long or short.
On average, "somewhere between 50 (percent) to 70 percent of tenants move out each year," says Steve Lefkovits, publisher of MultifamilyRevenue.com.
Although there are some parts of the country with their own unique moving seasons, moves in and out tend to occur from May through early September, Lefkovits says.
From a landlord's viewpoint, it's often advantageous to have a lease expire during the busy season, when a tenant can be found more easily. Therefore, if you're starting a lease in March, there may be a rental-discount incentive if you take a 15-month lease ending in the next summer.