property management - incentivizing quick turnover of units

[Kristi Burmeister]

I use a property manager to manage my portfolio and one of my big concerns is slow turnover of vacant units.  Between getting a unit ready for showing, showing, and leasing, it can take a few months.  I'm wondering if anyone has any ideas for incentivizing property managers to turn units quickly.  For example, offering 100% of one months rent instead of the typical 50% commission if the units are turned in X amount of time.  Does anyone have any ideas?  Also, does anyone have any rules of thumb regarding how quickly units should turn-over?  I'm talking about apartments in a desirable part of town with low-inventory.  thanks!