Your argument: "Being poor does not stop people from buying smart phones". The evidence for your conclusion: seeing many panhandlers and other assorted "street people" using smart phones. While your anonymous anecdotal evidence is compelling, the counter argument "poor people are less likely to own a smart phone" is backed by actual "research". For instance, a Pew study published in 2011 that considered the adoption rates of smartphones among different demographics concluded that
Smartphone ownership is highly correlated with household income.
(link), drawing this conclusion from the 22% ownership rate among households with an annual income of less than $30,000.