Trulia.com will certainly help you advertise your commercial properties however you'll be very limited considering whether or not you're a licensed agent. I will say this much out of all the third party websites out there this is in the top 2 for sure. If you need any help feel free to contact me.
"EVERYTHING I TOUCH TURNS TO SOLD!"
Keller Williams Realty
Real Estate Consultant
3xUS Army Veteran