iPhones were expensive, so iPhones were mostly used by wealthy people. That made it attractive for companies to make iPhone apps: not because of market share, b

iPhones were expensive, so iPhones were mostly used by wealthy people. That made it attractive for companies to make iPhone apps: not because of market share, but because it was targeted to those willing to pay. Software developers were happy for the busy-work, and once a company had its own iPhone app they might as well mention it in their marketing. The public saw all this focus on iPhones and concluded that they must be more popular than they actually were (i.e. the only thing more desirable than a status symbol, is a status symbol you think everyone except you already has!). That boosted sales, making it more popular but reducing its correlation to wealth. At that point it was firmly established culturally, technologically, economically, etc. which makes it attractive via the usual market share arguments.