I know that folks who rent holiday homes tend to rent to foreigners, who will generally access the main booking portals such as booking.com, AirBnb etc from outside Turkey. However, there is a market for domestic rentals as well, lots of folks from Istanbul and Ankara head off to the coast during the summer the same as those from abroad.
As it stands, booking.com has been blocked domestically since March last year due to a complaint by TÜRSAB that it was unfair competition.
Now TÜRSAB is targeting another twenty online booking sites such as Expedia, AirBnb - even SkyScanner is on the list!
Given the current political climate I suspect they will be successful.
TÜRSAB have indicated that they are still in discussion with booking.com, so who knows what'll come of that, but on the basis that they were banned almost eighteen months ago it doesn't look hopeful.
JF