While the ladies might like your ability to surprise them, that is not the case with your readers (not necessarily, at least). If you are trying to build a popular blog with loyal visitors, you should have a clearly outlined posting frequency.
Sometimes you want to go even further. Apart from having a fixed posting schedule it is also a good idea to write about certain topics and use specific post formats regularly.
Ever noticed how most mainstream newspapers have sections and columns scheduled on specific days of the week? Technology goes on Wednesdays, Career & Jobs on Mondays and so on. This structure enables the readers to know what information they will receive on any given day, and they can adjust their newspaper reading habits accordingly.
This principle can also be applied to blogs. The Zen Habits blog illustrates the point perfectly. Leo Babauta, the author, covers specific topics on fixed days of the week: Productivity on Mondays, Finance on Tuesdays, Simplicity on Wednesdays, Happiness on Thursdays and Health on Fridays.
You certainly don’t need to be as methodical as that, even small commitments towards a regular schedule will help. Do you use “speedlinking” posts, for instance? You could reserve a single day for them. Do you have at least one “pillar” article weekly? Why not publish all of them on a specific day, say Monday or Tuesday?
As far as blogging goes, being predictable is a virtue.