Major League Baseball has to be pleased with the ratings for the first 2 games of the World Series. I believe the 2 factors that have helped increase the viewership of these games are the teams playing in the World Series, and the earlier starting times.
Although many people think that the New York Yankees will automatically help the ratings, it is the competiition that makes the difference. In the 90s, when the Yankees were winning, there were a few series that were very low rating. When they played teams like the Padres and the Mets, there was not much interest. Playing a team like the Phillies that is more evenly matched and has as many All Star players as the Yankees helps the ratings.
Also, the earlier starting times have made a difference in the ratings. After years of starting the games at 8:40 ET, MLB finally has done the right thing by having first pitch just before 8pm ET. This has added increased viewership, and I truly believe more people will invest more in the series knowing they can watch until the end. I would like MLB to take this to the next step and have the World Series games start earlier on the weekend. I understand the reasons for not having afternoon games on weekends, however, I believe they can start the World Series games earlier in the evening. For the Saturday night games, they should start at around 7pm ET, and on Sunday, they should start at 7:30 (immediately after football). This would be a great gesture to the fans, and I believe the ratings would not affected by this.