I write my own. It’s not as difficult as it might seem.

  First, get a MS Office or Publisher custom template made for your practice.   Then write 1,000 words or so on the current state of whatever is on your mind, run it by compliance and drop it into the template. Print it on the color printer and good to go.   Maybe a days worth of work in total, but my experience is that it's very much worth the effort. Clients can tell it's my writing and often voice their appreciation.   Also I believe it is a much more effective way to drip on prospects than to use any "canned" piece.   I send it out at least quarterly, but can obviously put one together very quickly if market events might dictate it.