Best Sources for Advertising Commercial Real Estate?

[Kingalan1]

After spending over $50,000 and 3 years on web site development and SEO I realized that advertising on such commercial real estate sites as Loopnet and Cityfeet were  more cost effective for developing leads for identifying businesses seeking commercial space in New York City. My firm is a tenant rep brokerage assisting tenants in the acquisition of office, showroom and commercial lofts space in Manhattan.

When my firmswitched to Loopnet I was astounded that this site generated leads at a lower cost and a greater quantity than my private branded website (www.metro-manhattan.com). I would have thought that a private branded site would be more effective.

Now 2 years later I am having issued with Loopnet and can no longer advertise there.

Does any one have any suggestions concerning business websites where we can  advertise commercial tenant representation services in Manhattan? Sites like www.officespace.com look like they have potential. LinkedIn sounds like a good demographic but I am concerned that advertising would only generate requests for links rather than generating bona fide leads.

Thoughts???

Thanks, Alan