We'd start this post with a "stop us if you've heard this one before," but for two reasons -- the first being that you have certainly heard this news before, and the second being that you've heard it often enough that we've probably already rolled out the "stop us if you've heard this one before." And because we don't want to stop, and because you've certainly heard this news before, we'll just go ahead and say it -- January was another month of (incrementally) increased rents and (notably) tightened vacancies in a NYC rental marketplace that has been defined by those trendlines for months now. This is the thing with trends, of course -- they tend to be linear, and they tend to be difficult to blog about without repeating oneself. The problem, here, being that -- when it comes to Manhattan rental listings over hte past few months -- the trend has proven to be especially persistent. How much so?