Bottom line is: I really want to focus on my projects that have high revenue viability. I'm not experienced with monetizing free products, but someone else is. Until then, having threewords.me on my back is extra baggage that I'd rather let someone take care of, so I can focus back on what's important for me: creating profitable startups.
I had the opportunity to take six-figure funding amounts from big firms and individuals, but I said no to that. I'm passionate about building better support systems for startups. I'm passionate about building an OpenTable competitor. I don't feel the same passion with threewords.me, and since I never take capital on something I don't really think my soul has a connection with (to go all zen on you), the other option was to sell it.
I really appreciate the kindness of the Hacker News folks for taking an interest in the threewords.me 'saga' (thank you!) but I'm admittedly a little embarrassed because the image that all this coverage is putting out for me isn't something that I actively pursue. I secretly hoped that the threewords.me sale wouldn't hit HN, and was satisfied (until now :P). It's just a side project that went big.