I purchased the Economist GMAT course for 3 months , and genuinely did NOT expect to get a 50 point increase. I thought that I had reached my peak of maths / quant knowledge, and was fully expecting to be asking for a refund after I retook the GMAT. My focus was now 90% on the Economist course, occasionally (and less than I should have) dipping back to OG questions, looking at Magoosh lessons, or doing the odd CAT with MGMAT or Veritas. My theory was that they would not put together the course in that fashion and with that guarantee unless they had faith that their system worked. Clearly it did! I worked 1-3 hrs per day, taking a complete day off every other week or so. The Quant stuff was really good, and I picked up some great techniques and explanations for concepts I'd really struggled with ; the Verbal stuff was "meh" (I never really got into the idea of learning a whole bunch of rules - I'd always done fairly well simply going by what sounded right); I largely ignored IR; and I had little faith in their AWA assessments (one scored me a 3 for an essay which in my mind was at least a 5). The Ask-a-tutor facility was very useful, and the online tutoring sessions depended entirely on who was tutoring at the other end.