I caught the last 20 minutes of Smackdown last night, and I haven't watched Smackdown regularly in over a year. I actually made it a point to get home to turn it on so I could see the main event.
Why? Because WWE gave away the massive ending - Alberto Del Rio defeated Big Show in a Last Man Standing Match for the World Heavyweight Title. This isn't the first time they've done something like this, it's not even the first time in the last two weeks, they gave away Wade Barrett's Intercontinental Title win, and I'm sure it won't be the last, but it worked well last night.
I certainly don't think this is something WWE should make a habit out of, because I'm generally a surprise-oriented guy, I like to be wowed. but they had the right idea here. Had they not spoiled it, I wouldn't have known about it until this morning. I don't read dirt sheets anymore, I don't visit wrestling websites that would post anything like that and I don't live on Twitter these days either. So in this case, WWE got me to tune in.
Sometimes a spoiler can take me out of a match, I couldn't imagine enjoying the Royal Rumble if I already knew the winner, and I wouldn't want to watch WrestleMania a day late if I knew the results. But for a Smackdown that I wouldn't have watched anyway? It gets people tuning in, restores (at least temporarily) the notion that big things can and do happen on Smackdown, and perhaps most importantly, could boost ticket sales. If someone wasn't thinking of going to Smackdown because it's just the taped show, now they may be more inclined to show up.
From most accounts, WWE executed this title change well, they just need to wait a few years before doing it again.