Three may have been the magic number for hip-hop trio De La Soul, but it is losing its influence with retailers.

As shifting pricing strategies and the growth of the discounters transform the UK retail landscape, supermarkets are moving away from the established three-tier ‘good, better, best’ approach to own-label ranging.

Although premium products continue to play an important - or even more important - role in differentiating between retailers’ offers, the boundaries between lower tiers are blurring. And own-label offers are becoming more sophisticated, as retailers and their suppliers roll out new ranges thatd are, in effect, brands themselves and offer specific cuisines or target special diets.

Exclusive research by The Grocer using data shows that, in the past 12 months, each of the big four has reduced the number of SKUs in its bottom-tier ‘value’ range. The change has been reflected in a drop in sales of value-tier products, from £3.5bn in the year to 2 March 2014 to £3bn in the year to 1 March 2015.

So with the PLMA’s World of Private Label trade show just weeks away, what key category changes should attendees be thinking about, and how can they address them?