One of the key successes that Tesco had was managing to create a single brand that appeals across all consumer ranges, selling both cheap and premium goods under one core brand. Since then it's become ingrained on the cultural psyche that you get few preconceptions of what a Tesco store is and who it appeals to, it almost just "is".

In the UK, on the higher-end you have Waitrose and M&S Food, on the upper-middle Sainsburys and (before it closed) Safeway, on the middle-to-low end you have Morrisons and Asda and on the low-end Aldi and Lidl. Tesco totally transcends that, selling budget ranges similar to Aldi and Lidl, having prices comparable to the middle-to-low end supermarkets, and selling high-quality goods similar to the high-end supermarkets. I was talking to my Dad about this earlier and he was explaining in the 70s and 80s how Tesco were largely a low-end budget supermarket and how this was a massive shift in the early 90s which lead to them getting the upper hand on Sainsbury's in the market.

This was combined with a move towards large-format stores selling a mixture of non-food goods which weren't popular in the UK until then, movement towards smaller inner-city stores to extend their brand, the fact that unlike other supermarkets Tesco had less of a north/south divide and, of course, the Clubcard.