If the goal of Sprint’s latest promotion was to bring customers into its retail shops, it appears to have succeeded. 

According to new research from Placed, a company that tracks location through mobile phones on an opt-in basis, the first week of the “Cut Your Bill in Half” promotion increased foot traffic at Sprint retail shops by 700 percent week over week compared to competitors AT&T, T-Mobile and Verizon. 

That kind of interest didn’t last. The percentage increase in week over week store visits fell off in the second week of the promotion to just 4 percent over competitors. 

In all, Placed says Sprint gained 51 basis points in marketshare across wireless carrier store visits since the start of the promotion, equating a 2.96 percent increase.

According to iSpot.tv, Sprint’s TV ad spend increased by 54 percent from the week prior to launching the promotion.