First, we do two monthly newsletters with about four pieces of content each (different subjects) and both get more opens than weekly or our brief daily annoyance. In my high end B2B world, quality always trumps quantity. And my longest pieces (1500 words+) do much better, including time on page, which is a stronger metric.
The more important factor is the framework you’re using to build out your content strategy. Do you have a series of pieces that address each stage of a buying research and decision process? Are they linked by a cornerstone round-up piece? Does each point the reader to a logical next information piece with interlinking? This is not about cranking out endless blog posts and thought pieces. You have to work harder and leverage the good stuff you already have. And every piece should contain some kind of social proof- a quote, an example (with names), etc. I know this isn’t easy but it will amp up your content strategy.
I no longer even consider quantity over quality. It is too simplistic, in my opinion, these days, to simply set a schedule and then find something/anything to fill in the slots. They have to be interlinked and anticipate the needs of a buyer, at each stage of their information gathering process.