The world of databases and information is expanding, and while knowledge may be power it also has a price. And that could become an increasing burden on those who have to buy it. The essential reason for the success and efficiency of the multiple grocery trade has been its ability to harness technology to decision making. Academics and analysts are sometimes guilty of measuring without a clear-sighted objective. The result? A mountain of paper, statistics and interpretations which only lead to confusion. But the UK grocery store groups - and latterly wholesalers - have shed this expensive and unnecessary luxury and concentrated on discovering how many beans make five. Their questions have produced stock and profit analyses, stockturn figures, shelf allocation tied to sales, and ordering systems linked to central warehouses which have slashed delivery costs and rendered obsolete supermarket storage areas. And now all this information, and reams more, is for sale to interested parties, mainly suppliers. There is a snag, or is it an advantage? The purchaser after buying the trading data from one store group, will have to repeat the process with all the buying companies if he wants the total picture. Also involved in data sales are many others, including associations, umbrella bodies, market research companies, newspapers and magazines. And of course there is on-line information through the Internet as well as in a legion of documents, books and directories. The raw data from multiples may be the key to knowledge but the reasons for the shelf decisions will remain firmly in the hands of the individual retailers. And they have different views and policies about stocking and pricing. There is an obvious thought that much of this data could be pooled and then sold, making the process perhaps more central and less expensive. But if grocery retailers imitate, they seldom co-operate. It seems that data sales will flourish on the basis that manufacturers need to know - even if the news is bad and costly. The paper mountains will grow.