( CNN ) -- If the trajectory of American daily life keeps heading in its current direction , the country may end up with only two dominant occupations : . -- Carrying stuff in boxes to people 's houses . -- And keeping a watchful eye on those same people so they do n't hurt each other or steal things when they do leave their homes . For all the talk about how e-commerce is outpacing the performance of traditional retail sales in brick-and-mortar stores , the men and women who could gain the most from the boom in online merchandising are not Web designers or those who come up with clever new shopping apps , but workers who perform one of the oldest jobs in the world : . Lugging packages from the curb to someone 's front door . It 's one task that ca n't be accomplished in cyberspace . During the 2013 holiday season , according to the Wall Street Journal , retail stores drew only about half of the foot traffic that they did three years earlier . And during the peak holiday shopping period , online sales increased by more than double the rate of sales at traditional stores . For every shopper who does n't leave a store carrying a bag full of merchandise , but instead places orders online , there 's someone who has to bring those items to the residence . And in the long run , the major beneficiaries of this shift in habits could very well turn out to be the people who undertake a decidedly low-technology endeavor : grabbing a box from the back of a truck and walking with it to a house . You can already see the effects of this in statistics kept by the United States Postal Service . It 's no secret that , in our era of e-mails and texts , the number of first-class letters delivered by the post office has plummeted . As recently as 2008 , the Postal Service reported that it was delivering 90.7 billion letters annually . By last year , that number was down to 65.8 billion . But the Postal Service 's numbers for delivering packages , as opposed to letters , have actually gone up . In 2008 , it delivered 3.3. billion packages ; that had grown to 3.7 billion packages by last year . United Parcel Service says it delivers 16.3 million packages and documents worldwide every day -- 4.1 billion a year . Some time-honored , pre-digital-era manufacturing firms have figured out a way to make the lug-the-package-to-the-house business model work for them , too . International Paper Co. , according to the Journal , `` is among the companies profiting from new digital habits . It bought several makers of corrugated cardboard boxes , which now fill with goods shipped by online retailers like Amazon . The Memphis-based paper company said it has a 35 percent market share . '' But if carrying boxes is one line of work that has legs , another -- just as old-line -- may become even more in demand as the years go by . We can tell ourselves that our worlds are full of social media friends and amiable followers , yet the growth in industries devoted to protecting us from each other , both on the streets and in the electronic ether , betrays a certain distrust in the purportedly benign intentions of our fellow citizens . It 's not just the checkpoints at airports , and surveillance cameras on street corners , and cybercrime-fighting software offered by manufacturers ; Samuel Bowles and Arjun Jayadev , writing in the New York Times , noted , `` another dubious first for America : We now employ as many private security guards as high school teachers -- over one million of them , or nearly double their number in 1980 . ... What is happening in America today is both unprecedented in our history , and virtually unique among Western democratic nations . The share of our labor force devoted to guard labor has risen fivefold since 1890 . '' This caution on the part of both citizens and industry may be warranted , but Bowles and Jayadev , reflecting on the melancholy underlying message of this , point out what philosopher John Stuart Mill wrote in 1848 : `` It is lamentable to think how a great proportion of all efforts and talents in the world are employed in merely neutralizing one another . '' Neutralizing one another or , more cheerily , showing up bearing boxes . The Postal Service reports that its letter carriers and package-deliverers drive 4 million miles every day . UPS operates a delivery fleet consisting of 96,028 cars , vans , tractors and motorcycles , as well as 237 aircraft . As the inexorable shift to e-commerce becomes the standard way of shopping , those numbers can only be expected to increase . And the private-security industry ? That other growth field ? There is an outside chance that it could eventually dwindle : if we should someday decide to put our faith in the sweet intentions and endless goodwill of our fellow citizens , both the ones we can see and the ones who invisibly make their way into our computers . Until then , though , there is a multitude of home-security and break-in-alarm products for sale online . And a multitude of men and women hired to carry them to the double-locked front door .
Bob Greene : America may end up with only two dominant occupations . Greene : One is carrying stuff to people 's homes , the other is protecting them . He says with the rise of online shopping , more people need delivery services . Greene : The other growth field is private security ; we employ more guards now .