In the 1980s Mexico was going through a severe macroeconomic crisis. In those years an artist rose to stardom: Chico Che, together with his band La Crisis. Among several hits, "Quién pompó" became a favorite.
Quién pompó is a childish version of the question quién compró (lit. who bought this). In the context of the song, the question is a hint towards the ugly truth that a lover has succumbed to the wealth of another man, who buys her love with gifts.
Quién pompó is generally used to call attention to somebody's new and shiny things: clothes, accessories, gadgets, rides, etc. It is not offensive but quite colloquial.
The video below shows Chico Che y la Crisis' song "Quién pompó". Even though this is not Chico Che but an impersonator, da el gatazo.