tr.im your URLs. tr.im is stopping their service. After the end of the year, redirects through it will no longer work.
We regret that it came to this, but all of our efforts to avoid it failed. No business we approached wanted to purchase tr.im for even a minor amount.
There is no way for us to monetize URL shortening — users won’t pay for it — and we just can’t justify further development since Twitter has all but anointed bit.ly the market winner. There is simply no point for us to continue operating tr.im, and pay for its upkeep.