I imagine this term was coined on the analogy of the BE idiom "the Rolls Royce of" (referring to an iconic high-quality motor car brand). Google shows "Google of" as outnumbering "Rolls Royce of" by about 3 hits to 2; but that corpus is rather biased. . BNC has "the Rolls Royce of" outnumbering "the Google of" by 4 hits to 0. And even Google, if restricted to UK pages, shows RR as outnumbering G.