The two took different approaches to their actions today, and they complemented each other well.
Should Google have taken a stronger stance against SOPA and functionally disabled its search service for the day? Earlier in the day I saw a few people arguing that Google, the number-one most visited site on the Internet, should have pulled a Wikipedia, which holds the number-six spot. Whether you agreed with the protest or not, it seemed indisputable that doing so would have been a stronger statement.
But, now, at the end of the day of protests, I wonder if Google's more subtle position -- blacking out only its logo -- wasn't as effective as Wikipedia's total blackout. After checking out Wikipedia's blacked-out site early in the day, I just didn't visit it again. But Google I used all day, many times, and each time I was reminded of the ongoing protest.
The real strength was not in either's particular approach but in the two together. Without Wikipedia's more splashy approach, Google's black box may have been too small to draw much attention. Without Google's day-long reminder, Wikipedia's blackout might have seemed like the action of a fringe group, the diehards of the site. But cumulatively, along with the many other sites that protested in big and small ways, the statement was powerful. The New York Times is now reporting that 4.5 million people have signed Google's petition against these bills.
Of course, in the end there's really only one metric that matters for effectiveness: whether these bills -- and similar ones down the road -- find their final resting place in the dustbin or in U.S. code.