Complex sentence: The retailers black Friday sale in its staples corner outlet sold laptops and other electronic devices for under £50, since then other major online retailers like Amazon, Littlewoods, Cotswold Outdoor and Apple.
Split into simpler sentences: The retailers black Friday sale in its staples corner outlet sold laptops and other electronic devices for under £50. Other major online retailers like Amazon, Littlewoods, Cotswold Outdoor and Apple.