The cash & carry giant's symbol group was relaunched in March with new classifications for medium and large stores, as well as a new fascia called Premier Express for c-stores under 800 sq ft.
Booker had attracted 285 retailers since March 166 new retailers and 119 converted stores, said Steve Fox, Booker's sales director for retail. Sales in new stores were up 20% to 30% in some cases.
The Premier Express fascia had proved to be the most successful, gaining 130 new stores over the past eight months.
"We had actually only targeted for 100 Premier Expresses within 12 months, so it's fantastic we've had such success," said Fox. "Some of the stores we've taken on are in great locations with a high footfall and they've moved over from traditional CTNs or off licences."
Loyalty had remained high, with just 14 retailers choosing to move to other symbol groups during the period. A further 82 stores left the fascia but continue to be supplied by Booker.
The chain aimed to recruit more than 1,000 new Premiers in the next three years, Fox added.
Booker's Premier management team has grown from three retail development controllers to six during the period to keep up with the expansion.
An EPoS system launched six weeks ago had already been taken up by 50 retailers, said Fox.