Made for only $1 million, Dr. No grossed almost sixty times that worldwide, a budget to box-office ratio that no other Bond film has been able to beat.
The producers maximized Bond's money-making potential, not by putting all their money on the roulette table and letting it ride, but by cleverly staging double features of Bond films, like Dr. No and From Russia with Love, and withholding TV rights for as long as possible. In the days before Netflix, everyone eagerly gathered around the TV when Bond was on and sat through all the commercials. (Source)
Because of the combination of on-screen cool and behind-the-scenes smarts, millions of people around the globe saw Dr. No and came down with Bond fever. No made Sean Connery a household name, meaning without Dr. No, we'd never have had "You're the man now, dog."
But it's the people who make Bond today are perhaps the biggest fans of Bond. For the 40th anniversary of Bond, screenwriters of Die Another Day, Neal Purvis and Robert Wade, included many homages to the Bonds of yore. (Halle Berry's saltwater-soaked entrance was a clear reference to Honey Ryder's debut in Dr. No. She made a splash that is still felt over forty years later.) (Source)