Interesting. Not saying I don't believe you, but I'm interested in what a company might perceive to be the value of being part of the S&P 500. Is it just a reputation boost? Or is there something concrete?
There is a massive value. It means that all SP500 tracking ETFs ($SPY, $VOO etc) have to buy your shares. It's a huge boost to your share price, especially with the rise of passive investing.