We've been blogging now for around 3 years and do keep track of what gets traction and what doesn't -- here are some things we've noticed:
a) Monthly market reports (which is what makes up for 95% of most Realtor website blogs) get VERY LITTLE action. Especially the type of market reports that are straight from TREB's market watch numbers. "Interesting" market reports do much much better (like the infographic example)
b) Project specific - we do a lot of condominium projects, and depending on the "hot" project of the month, that particular project will get a lot of action. This month, Bond Condominiums, Yorkville Plaza and B.Streets have all been smoking hot (and we have VIP access to all 3! :) )
c) Rendering posts: People love to see images. Anytime a new development releases renderings, we devote an entire blog post to them.
d) Special Offers: Who doesn't love special offers? If ICE CONDOS are selling at 10% down and cheap parking, our readers what to know about it!
e) Market analysis of specific projects: Full market analysis of individual projects really set us apart in our early days (Example here for THE YORKVILLE - http://www.talkcondo.com/toronto/the-yorkville-residences
) However, each analysis takes a minimum of 8-12 hours to prepare which is probably why we don't see a lot of Realtors do them but they are hugely relevant and beneficial to our readers.
Nowadays, developers don't like us releasing pricing information so early - so we only send these reports out to our newsletter database and then the website gets updated once the pricing information is public (sign up to our newsletter here: http://www.talkcondo.com/subscribe
f) Voice - this isn't a "post type" but ultimately your readers are coming to you for your VOICE - who you are and what you say. Your posts should reflect this. BuzzBuzzHome are a perfect example of a site with a VOICE and PERSONALITY. Their readers know who they are and they are true to themselves. There are agents out there who have done an incredible job of finding their "voice" online. This above all else is the most important aspect - once you find your voice, it becomes very easy to figure out what people come to you for.
Hope that helps!