The most profitable asteroid is…

With the recent announcement of the asteroid mining company, Planetary Resources, some of the most-asked questions about this enticing but complex endeavor include, what asteroids do we mine? Which are the easiest asteroids to get to? Could it really be profitable?
While Planetary Resources officials said they hope to identify a few promising targets within a decade, the initial answers to those questions are available now on a new website that estimates the costs and rewards of mining rocks in space. Called Asterank, the website uses available data from multiple scientific sources on asteroid mass and composition to try and compute which asteroids would be the best targets for mining operations.
So, which asteroids are most profitable, valuable, easily accessible and cost effective?
The winners are, according to Asterank:
Most Profitable: 253 Mathilde, a 52.8 km-diameter C-type (carbonaceous) asteroid that has an estimated value of over $100 trillion and estimated profit of $9.53 trillion (USD)
Most Cost Effective: 2000 BM19, a very small O-type asteroid (less than 1 km wide) that makes several close approaches to Earth. Its estimated value is $18.50 trillion and an estimated profit of $3.55 trillion.
Most Valuable: 253 Mathilde
Most Accessible: 2009 WY7, another small asteroid with regular close approaches of less than 1 AU. This is an S-type asteroid, a silicaceous or “stony” object that has a high accessibility score on Asterank of 7.6577.
Asterank combines both the economic and scientific features of over 580,000 asteroids in our solar system, looking specifically for platinum-group metals and water. It was created by Ian Webster, a software engineer in the San Francisco Bay Area.
“I’ve always had a strong interest in astronomy and especially space exploration,” Webster said via an email to Universe Today. “The commercialization of space through ventures like asteroid mining really excites me because I believe it’ll open space to the rest of us and improve human quality of life. My day job is at a startup unrelated to space, but my hobbies include building rockets and many side projects like this one. I have a lot of fun applying computer science in different ways and I hope that Asterank will educate and inspire people.”