For whatever reason, my sales stopped abruptly right before I needed 1 more sale for the next tier. Anyone else experience this?
Nope, still need that 1 sale to get into the next tier. Been needing that 1 sale since dec 15th or so!
If you are running a scripted site, then I believe that you must have been hit by the dup-content penalty where all your pages are now supplemental. If this happens then sales, virtually all sales, simply dries up. On occasions (more than once), this has happened to me too.