Well the funny thing about "number one" is that it can be defined in so many ways. It's a good marketing tack.
https://www.google.com/search?q="we+are+the+leading"
https://www.google.com/search?q="leading+provider"
https://www.google.com/search?q="leading+source+for"
Every press release: "Foo Corp., the leading noun-er of noun, announced today..."
Googling site:prnewswire.com "the leading" - https://www.google.com/search?q=site%3Aprnewswire.com+"the+l... - "About 98,000 results".