In the 21st century, we invented a new genre of celebrity who were seemingly famous for nothing other than being famous. That's where Perez Hilton came from; he was just a blogger who wrote about famous people, and he did it so often and garnered so much attention that he eventually became famous in his own right. It helped that he had a stage name - not that he ever spent any time on stage - that was a memorable play on words.
Hilton is actually of Spanish descent, hence his real name, which is Mario Armando Lavandeira, Jr. That was never going to get the attention-craving blogger the spotlight that he so craved, so he jumped onto the coat-tails of Paris Hilton as she rose to celebrity prominence, respected his own heritage by changing 'Paris' to 'Perez' and soon he had the most must-see blog anywhere on the internet.