As the graph shows, Asda has a particularly strong fit to the catchment of the store, which opened in November last year.
Only Kwik Save, with its strong Welsh heritage, has a better demographic fit to the catchment based on CACI's Acorn analysis of BMRB's TGI survey.
Asda is particularly strong among the following Acorn groups who are all highly represented within the catchment: council estate residents, better-off homes; skilled workers, home owning areas; new home owners, mature communities.
This demographic fit means Asda may achieve better returns on the store than would normally be predicted by CACI for a 40,000 sq ft store in such an area.
Without the demographic adjustment CACI predicts the store would be ranked in the middle of the portfolio in terms of both sales and sales per sq ft.
However, this prediction loses some gloss when the impacts felt by the seven Asda stores in the vicinity are taken into account. The table (bottom right) shows that the resulting net impact is an increase in sales of £585,000.
Tesco also has a considerable presence in the area and is likely to feel the most impact within its six local stores. It looks set to lose £167,000 a week from these stores.
Somerfield and Kwik Save in combination have a huge presence in the area and see a correspondingly large impact as a result of the new Asda. Safeway, Sainsbury and Morrisons are largely insulated from any impacts by their limited presence in this part of Wales.
Tesco is likely to hang onto its position as local market leader, taking 38% of trade from the catchment of the new store (chart).
However, Asda is close on its tail and may achieve even more than the predicted 33% once the demographic fit is taken into account.
The other major multiples are remarkably weak in the local catchment, and the other usual UK majors are pushed behind Somerfield/Kwik Save which take the next largest chunk of market share, at 11%.