If you keep chopping away big parts that aren't conducive to e-commerce; the 6.40% is going to be a pretty big percentage. Small specialty stores are probably hit especially hard, to the point of being crushed; going out of business and making the e-commerce players a larger percentage of the market and thus more efficient, driving even more e-commerce in a positive feedback loop.
The only visible effect of e-commerce has been the thinning of margins. The ability to check prices online leveled the playing field between retailers and customers. This has brought us closer to a real market -- one where perfect information is available to all parties.
They're selling Apple products to mall goers, which are a known diminishing supply, and is selling access to same-day accessories and acting as a front point for talking to Apple techs and dealing with warranty claims.
In that sense, Apple stores are actually in the business of selling services, rather than products.