Do we buy because we want to?

Americans today spend about twenty present more time consuming main stream media radio television internet. Whether we like it or not, the majority of this time is spent being bombarded by advertisements that try to appeal to consumers. Something I find interesting about consumer psychology is how advertising agencies use different stimuli to influence the consumers, possibly persuading the to choose their product over another companies. These stimuli that are used are called interpersonal influences and contain but are not limited to social and cultural groups. Advertisers and marketing agencies use these stimuli, things we find amusing or repent things we want, to affect our attitude towards a product based on the target market we fall into. Considering that we are bombarded by advertisement every day from television, the Internet, radio, and now even video games it makes me wonder if we actually purchase these objects because we actually want and need them or is it because the stimuli make us think we do.