Google parent Alphabet (GOOG) just announced a quarterly dividend — adding to the S&P 500 dividend average. But don't get your hopes up too high.X The company is paying just 20 cents a share starting on July 17. Assuming that dividend is paid four times a year, Alphabet will yield just 0.51%. That's a paltry dividend even by S&P 500 standards.At 0.51%, Alphabet's yield is less than half the 1.3% paid by the S&P 500. It also ranks 377th out of the S&P 500. It's also small next to some other tech giants' tiny ...