I own a small corporate housing company. We provide fully furnished apartments for rent on a daily, weekly, monthly basis. Currently using Airbnb, Booking and Craigslist ads to find guests/ tenants. How do I research which way is best to reach out to people?
You may want to consider using Facebook Marketing and Google PPC (Pay Per Click) and the Google Display Network to create ads to display to your tarket market.
Here is Australia there is a big market for Executive Rentals which may just be your Corprate housing keyword.
You can define your ads to only display to people in your city. The way to work with this is to create a landing page so when a person clicks the ad they are sent to a specific page which lets them know of your specialised service of finding the best property and how you facilitate this for them.
On that landing page your goal would be to capture their email address and then you can send them the best properties to help them.
You can also regularly blog about renting strategies and the best place to find excellent rental property and become the place to go to find the best executive/corporte rentals.
Additionally with Facebook marketing ads you can target companies, brands and refine your target so your ads are displayed to the most relevant people looking for rentals like yours.