The Last Silent Films

According to this article, why did Hollywood switch over to "talkies" so fast? Why was 1928 such a pivotal year for silent cinema?

    Hollywood made the switch over to "talkies" so fast because audiences of the one of the first movies to use synchronis sound, the Jazz Singer, had shown how much audiences wanted to hear as well as see the films. Because of the revealed demand, Hollywood realized that it would be much more profitable and interesting to audiences if they switched to talkies. 1928 was such a pivotal year for silent cinema because it was the only year in which the silent film era and sound pictures intersected—silent films having essentially died out by 1929.