Marketers prey on these people, television shows extoll the virtues of appearance, and with credit while expensive available many of these people are just too easy to take advantage of.
you don't even have to be "poor" to be coerced into buying something too expensive for your household, Apple is the best example but many companies strive to build the got to have it mentality and personal electronics is has one of the lowest entry points for immediate recognition. Clothing isn't far behind, nor shoes, but the recognition factor outside a few brands isn't there. Cars are where its at in the middle to upper middle income brackets.
People will willingly spend themselves poor for a feeling of at least equality or success