To support his thesis, he examines the causes of why the majority of Canadian ice hockey players are born in the first few months of the calendar year, how Microsoft co-founder Bill Gates achieved his extreme wealth, how The Beatles became one of the most successful musical acts in human history, how cultural differences play a large part in perceived intelligence and rational decision making, and how two people with exceptional intelligence, Christopher Langan and J. Robert Oppenheimer, end up with such vastly different fortunes. Throughout the publication, Gladwell repeatedly mentions the "10,000-Hour Rule", claiming that the key to success in any field is, to a large extent, a matter of practicing a specific task for a total of around 10,000 hours.
The publication debuted at number one on the bestseller lists for The New York Times and The Globe and Mail, holding the position on the former for eleven consecutive weeks. Generally well-received by critics, Outliers was considered more personal than Gladwell's other works, and some reviews commented on how much Outliers felt like an autobiography. Reviews praised the connection that Gladwell draws between his own background and the rest of the publication to conclude the book. Reviewers also appreciated the questions posed by Outliers, finding it important to determine how much individual potential is ignored by society. However, the lessons learned were considered anticlimactic and dispiriting. The writing style, deemed easy to understand, was criticized for oversimplifying complex sociological phenomena.