Amazon has long drawn hackles from bricks-and-mortar retailers that allege the Seattle Web giant enjoyed an unfair advantage in states where it didn’t have to collect sales tax. That advantage came to an end recently when Amazon began collecting sales tax in Pennsylvania and Texas and in California starting over the past weekend.

But it may not matter anymore. A new survey by Wells Fargo analyst Matt Nemer showed that consumers in Texas, the second most populous state in the nation, essentially haven’t changed their buying...