Mark McClusky says for elite athletes today, pushing boundaries and breaking records is all about "the aggregation of marginal gains."
As hordes of Black Friday shoppers descend on stores in search of deals, many of them are armed with something that has retailers shaking in their boots: smartphones.
AOL’s Daily Finance news site reports that about 40 percent of shoppers with smart phones will use them to get a better deal online.
It’s part of a trend called showrooming that really took off last year.
Now retailers are fighting back by matching prices and offering free shipping on out-of-stock items.
But with sales from mobile devices expected to double this year, retailers may be fighting a losing battle.