In an injustice liable to turn us all into raging Marxists, the fact is, major labels have something of a monopoly on distribution in this country.
Macklemore and Ryan Lewis have been celebrated for topping the Billboard Hot 100 as independent artists, only the second time that has ever happened in contemporary pop music history. It was the result of a lot of groundwork, from relentless recording and touring to social media hustle.
But even in this supposedly-democratized era of music distribution, gatekeepers remain. In order for "Thrift Shop" to reach No. 1 on the pop charts, Macklemore had to deal with Alternative Distribution Alliance, a part of Warner Music Group. This isn't the same as signing to a major—there's no major label advance that needs to be recouped, and Macklemore handles his own marketing.
But in order to get his records in stores and receive airplay on par with major label artists, he still required a major label distribution network. No one can hit No. 1 without the big guys on their side.