This of course is probably true for normal shoppers, (though may not be for bulk buyers such as restaurants, hotels, pubs or other caterers - who will shop for single product bargains).However, we put an index of search terms together made up of all food stuffs and recipe ideas - it came to over 10m searches a month. Surely the supermarkets should be vying for that?It seems that some of the supermarkets are optimising for many, many food terms, and others are not.Cause or correlation, but the ones that are placed for multiple food terms and recipes are the ones that are doing best online - i.e Tesco.Why does Tesco have 50% of the online grocery market? In terms of organic search, that is being found in Google’s search results, Tesco is extremely dominant.I've created category specific indexes based on major search terms across the grocery sector eg frozen foods, online shopping, recipe ideas etc. The returning URLs for these keywords in Google’s search results are being tracked every day.As with the industry as a whole, Tesco is light-years ahead of the competition and it is no surprise that it has 50% of the ecommerce grocery market and is doing so well in the online shopping channel as its search positions dominate the sector.The example indexes are:General supermarket (search terms include: online shopping, groceries etc). Mother and baby goods (baby milk, nappies etc). Fresh food and recipes (fresh pasta, fresh fruit, recipe ideas etc). Food cupboard (large marmite, pancake mix etc). Within these groups are around 2,500 search terms with a monthly search traffic, according to Google, of over 10m in the UK.This data indicates that Tesco is by far the most visible supermarket. In fact all the other major supermarket brands hardly feature at all outside the general supermarket indexes. (all data from Pi Datametrics).