A U.K. REIT has produced some of the first hard data showing how opening a physical store increases online traffic for retailers.

British Land used data from data analytics and consumer analysis firm Connexity Hitwise to examine the effect opening a store has on online traffic.

The research found that when a new store opens, traffic to the retailer’s website from the surrounding postal area increases by 52% on average within six weeks of opening.

Digital traffic from the local area remains around this level, rather than dropping off.

It said brands with fewer than 30 stores enjoyed the greatest positive impact from store openings, with 84% uplift in local traffic to their websites on average. It said this showed that a physical store can make a critical contribution to the online success of expanding brands.

The research was based on a sample of 29 retailers opening at BL shopping centres between April 2014 and December 2016.

The research does raise further questions. Traffic increases from the postal area around a store, but do sales also increase? That question is key to determining whether the cost of opening and running the store is outweighed by the benefit of increased sales.

BL said it was undertaking more research with U.K. retail property body Reve to measure the distinct contribution of each channel and ensure leasing models and valuation methods reflect the benefit of the store to retail businesses as a whole.