According to the results of a three-month retailing trial carried out in the United Kingdom by the Unwins Wine Group, Percy Fox & Co and the Wine & Spirit Education Trust, well-trained retail staff will actively persuade customers to but better quality wine and ultimately sell more wine. The test concluded that an investment of £3,000 in training delivered a £44,000 uplift in sales over a 3-month period. It involved taking 30 stores from within the Unwins Wine Group and segmenting them into three groups of ten. One group was given no training, whilst the two other groups of stores underwent WSET Foundation Certificate in Wines. One of these two groups then went on to Diageo to take advantage of a Sales Training programme. According to the WSET, the results of the trial were conclusive. Sales in stores which had been through the WSET course grew by 6%, whilst those stores which also had sales training grew their total sales by 11%. The average amount spent on a single bottle of wine also increased from £8,26 to £8,49.