Sad to see tr.im go

I was saddened today to learn that my favorite URL shortening service tr.im has shutdown (CNET article here). Apparently they decided there was no way to ever monetize the venture so it was best to shut it down now. I must confess, I don't fully understand the Silicon Valley business models that allow companies (i.e. Twitter) to operate on such a large scale with no primary source of income, but that's a whole other discussion. In anycase, I appreciated tr.im while it was around and am sad to see it go...