The recent article of last month in my Big City paper, the LA Times elevates realty 
blogging to a place of absolute necessity and almost web royalty. The takeaway seemed to be just blog and success will come. Which of course reminds me of the old Web 1.0 adage, "build it and they will come". Which site owners eventually find to be untrue.
It seems with every new emergence of a platform comes a love affair. But let's focus on the current love affair with Blogging.
Blogs are just websites. There is nothing magical about them other than they give a user the opportunity to easily write and post content. Stuff they should have been doing on their traditional website. And it is easy to ping web service directories.
Here is the secret to getting traffic: Create content and get lots of links. The end. (of course if the content is not focused you get untargeted traffic. And try competing for a popular keyword without getting a ton of inbound links).
The only blog theme that makes sense to me is one that speaks directly to your future client.
It should serve them and no one else. Here is the equalizer. Ask yourself would a home buyer who is about to spend half a million dollars want to come to know you, or run?
Focus
Understand the difference from a vendor based blog or website, which carries a BtoB focus and sells to online Realtors and mortgage pros (Business to business). Versus a Realtor Blog which should be consumer oriented (business to consumer).
This single distinction may get you to change the focus of your blog.
In the end the best advice I can give is to remember your content is what magnifies your brand. Does anyone give a hoot that you went hiking last weekend? Unless it somehow illustrates the lifestyle of homeowners in that particular area, probably not.
