Corporate rentals are difficult. When I looked into it, you need to be quite close to where the offices are, even for a family home. Short term execs don't really value the ammenities of the far flung suburbs. If you are within 30 minute drive (rush hour) and have an unusually lovely area for families with lots of restaurants, parks, "walk to's", the location could work. Are there a lot of other corporate rentals in your area? That is a sign that this could work... sometimes one company places all their employees corporate rentals in one neighborhood.
Next, the place needs to be furnished -- nicely, too. It could be ikea, but no older than 18 months if using cheaper furniture like that. Beds need to be quite nice, new towels / linens, etc.
Next, you may want to consider weekly maid service (or every 2 weeks) and gardener for your coporate family rental.
Vacancy is higher, with only 1, 3, 6 and 1 year rentals on a full home.
All in, suddenly a small 3 bedroom town house, near the office and parks, with very nice fit-out and furniture makes a lot more sense than a sprawling 4 bed in the suburbs for that corporate rental.
The reason you need to make $6k is because of the wear and tear and replacement of furnishings / soft items with a corporate rental.
If it was a regular rental, it could be rented lower, but $4500 or more should be the target for unfinished, no gardener, etc, or you will lose your shirt. Gotta say, most homes can be bought easily for less than this, so it will be hard to get, I bet.