The systems are too inaccurate to be of any practical use to anyone who really wants to monitor beer volumes. If they really were of value to a business they would be taken up widely by independents - and they are not.

They record line cleaning and rinsing as well as beer flow without any mechanical differentiation. Such volumes are deduced by human beings, by rule of thumb. Rule of thumb is not weights and measures recognised. In any period measured the variances are wildly up and down and all over the place and can generate huge positive and negative variances. When you read the data alongside figures produced by accurate standard stocktaking methods variances can be hundreds of gallons up or down in any given six week period. May seem difficult to believe but once you've seen it in action any doubt flushes away.

As it is they are solely used by pubcos to instill discipline in tied tenants and the data has undoubtedly been abused in accusing people of buying out. Data has been used to levy hefty fines; tenants usually acquiesce for fear of costly litigation in defending themselves against aggressive big companies using full time legal departments to do all the work. Licensees cannot hope to risk the odds of losing - even when they know they have been wrongly fingered. Not good for customer relations.

But hey, who cares about customer relations when you routinely treat your customers like criminals anyway?