Less expensive, poorly designed machines see a drop-off in quality the longer they are in service.
Having 5 backlinks blogs with PR of 4 and 5 is greater than having 100 backlinks from sites with PR of merely one and 7. https://www.digitaljournal.com/pr/news/press-advantage/contractors-state-license-center-offers-contractors-license-school-in-san-fernando-valley