Editor’s Note: This article is reprinted with permission from Inman News. View the original article: "BlockAvenue aims to be Yelp for neighborhoods."

Think of the neighborhoods you love—or the ones you don't. Most likely, specific places pop into mind.

That's the idea behind BlockAvenue, a new service that rates the livability of urban neighborhoods using millions of data points, including user reviews via social media.

When BlockAvenue was in initial beta testing, "everybody that had something to say about a neighborhood always related back to a specific place," said Anthony Longo, the company's founder and CEO.

Having launched the service last month, Longo and his team are building it out first in New York City, Washington, D.C., and Boston. They'll add other urban areas nationwide in the coming months.

Google Maps anchors the search function of the site. When users search neighborhoods, letter grades—"BlockScores"—pop up over them. The best-rated 'hoods get A's, and the worst-rated receive F's. As a user zooms in, pins for restaurants and businesses appear, as well as user-generated reviews of specific locations.

"I still believe the neighborhood is online real estate's final frontier," wrote Brian Boero, partner at real estate consulting firm 1000watt, in a blog post that mentioned BlockAvenue's launch.

The tricky thing, Boero said, is that ratings driven by data "often feel random and unsatisfying"—BlockAvenue offers no explanation of his own neighborhood's "C" rating, he noted.

User-generated content presents a chicken-and-egg dilemma, Boero said. It takes content to build up a user base, but you need users to generate content.

If it were up to him, Longo said user reviews—now sourced through Facebook—will become the dominant factor in how BlockAvenue rates neighborhoods. Currently, crime data, school data, sex offender databases, and user reviews, among other data points, all inform the grades blocks get.

Since the tool is still in beta, the block rankings don't show up in every zoom level. For some rated blocks, it's tough to delineate exactly where the ranked areas start and stop.

Pins representing restaurants and other businesses drop in to the map as you zoom in. But the information about the blocks mined from social media is what stands out. Currently, the site works with Facebook, but is looking to integrate other social media platforms soon, Longo said.

"We wanted to build a Yelp for location," said Longo, also the founder of the lead generation and brokerage website CondoDomain, which was sold to Better Homes Realty in August.

At a certain close-enough zoom level, little green boxes with Facebook user photos pop up at spots where those users have left a note about that exact location.

"Houston is ostensibly one of the most famous streets in Manhattan, and standing at the corner of Orchard, it's easy to see why," reads one of the posts on a block in Manhattan's Lower East Side. "If you face south and look to your right, you see (New York City) institution Russ & Daughters. A few blocks down, treat yourself to a great egg cream and starchy snack at Yonah Schimmel's Knishery."

The poster's Facebook account is linked, so a user who wanted to know more about the neighborhood could easily contact the writer.

Right now, the service is free, but Longo envisions that as the service develops richer, more in-depth data, pro-level fee-based accounts will be available for real estate professionals and travel agents who would then have access to in-depth reports and trend data built from analyses of the system's many data points.

Along with revenue from membership, Longo says the company is looking at licensing and traditional advertising avenues as well.

As of now, the company has sliced the U.S. into 1.9 billion 300-foot squares, Longo said. But he wants to go at least one level deeper into neighborhood analysis, with user-delineated, custom-shaped neighborhoods. This would take venture capital funding and some high-level engineering, he said, both of which the company is pursuing.

Along with slicing neighborhoods like Manhattan's Tribeca or Boston's South End into 30 or more slices of rich, crowdsourced neighborhood reviews, Longo sees integrated restaurant and business reviews, possibly from Yelp, and Walk Score ratings showing up on the site, too.

With the service's hyperlocal focus, Longo doesn't see any direct competitors.

Walk Score, known for its walkability ratings of neighborhoods, released a very similar crowdsourced neighborhood review service today, iPhone app included.

And StreetAdviser collates users reviews of specific neighborhoods around the country, while Nextdoor, a neighborhood social networking site that raised $18.6 million in venture capital in late July, has entered the neighborhood-knowledge space as well.

San Francisco-based Findery is also playing with the emerging power of geolocation, map applications, and social media.

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Learn more about markets featured in this article: New York, NY, Washington, DC, Boston, MA.