The survey, from Reuters Business Insight and market research company TNS, shows that by 2006, the over-55s will be more valuable than all other younger consumers, worth £53bn of an estimated £104bn market for food, drink and household products.
The survey of 15,000 UK households found that the over-55s tend to trust established brands more, but are only slightly more likely than under-55s to stick with a brand that they like.
Brands that are very popular among older consumers, dubbed silver surfers, include PG Tips, KitKat, Silver Spoon, and Tetley Tea.
However, advertising's preoccupation with the 18-34 youth market means that the over-55s are not being reached effectively by advertisers. Only one in six in this age group say they buy a product often because it is advertised, while six out of 10 say they fast-forward through ads on programmes they have videotaped.
Few older consumers use ads to help them make brand choices or to drive their purchasing behaviour -- only a third of over-55s say they enjoy trying new brands, compared with 43% of under-55s.
The survey found that the age group clearly recognises that the vast majority of ads are not aimed at them, but rather younger viewers.
Ben Longman, consumer analyst at Reuters Business Insight, said: "Just as with the mainstream market, the 'grey' market is fragmenting rapidly. For marketers, consumers' age is only important in the context of other considerations such as consumer health, attitudes, disposable income and lifestyle. Marketers still have much to learn about senior consumers, and manufacturers have a lot to gain from getting it right."
The survey also found that over-55s shop more often than under-55s, but spend slightly less each time, and tend to shop around more and plan their purchases.
Almost half claim to buy British whenever they can, compared with 28% of under-55s, and older consumers spend £44 a head more than younger consumers each year on alcohol to drink at home.
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