This adds diversity to your mail campaign while also reducing the cost.

I reviewed some of the categories (topics) and saw many with well OVER 1000 different topics and thousands of posts to each of those diverse topics.

I have a pretty diverse portfolio.Flipped, buy-hold residential and commercial.Single family and multi unit.

No walkable amenities, traffic (cities have traffic, but you usually have the option to bike or take public transit), less of diversity and culture...  

When evaluating a market, look into these metrics:-Population growth-Job growth with higher wages-Business-friendly-Diverse economy-Strong occupancy rates-Acquisition price-to-rent ratio-Landlord friendly-Infrastructure development-Lifestyle amenities-EducationThen start building your team on the ground and take action!

Some of the parameters I look at - MSA population, recent job growth, future job growth, housing vacant, renters makeup, average rent levels, diverse, stable employers. 

Biggerpockets community is truly awesome through their diversity (buy and hold, wholesalers, bird dogs, commerce, developers, flippers, agents, etc).

Diversity is key but keeping in mind it has to be real estate. 

Luckily in DC we are close to many suburbs and a population that is stabilized by the federal government and a reatively diverse economy. 

Primary consideration IMO is a good market with diverse employment and a good management company.