Does tweeting lead to more action or less?

So at last night's Third Wednesday we discussed social media for social activism. Or, more accurately, if doing things like joining Facebook groups or tweeting about a cause even counts as activism.
The discussion was kicked off by some great points by Allison. She suggested that, well, tweeting is lazy and it doesn't really accomplish much by itself, but it's better than nothing.
The discussion was fairly animated, with lots of different points and points of view.
Here's where I stand, and I'd love to hear what you think:
Ala Clay Shirky's points about social media and action, I think that the more people you make aware, the more people you'll have actually do something. This is because you're always only ever going to have a small percentage of people willing to get off their asses. But, if you make tons and tons and tons of people aware (like, by tweeting) that small percentage will amount to a fairly large number of people. So, if only 1% of people who are aware will take action, it's better if there are tons and tons of people aware. So, in that sense, tweeting can help.
BUT: '"Announcing your plans to others satisfies your self-identity just enough that you’re less motivated to do the hard work needed," writes Derek Sivers, the founder of CD Baby. "Once you’ve told people of your intentions, it gives you a 'premature sense of completeness.'"' Link.
So, does tweeting count as doing something or talking about something? Does this mean that some or many of the people who tweet about a cause have made themselves less likely to actually do something, because now they feel like they already have?
But wouldn't people who are likely to get off their asses feel that tweeting isn't enough even if they do send out a couple just to tell other people?
I think I'd still suggest that more awareness could likely lead to more action. Yes, talking about something might make some people less likely to do something, but it would probably make a larger group more interested in taking action. Yes, I just used the words, think, likely, might, and probably.
What do you think?
Image from flickr user Petteri Sulonen



