Who knows what's going on behind the scenes, but as you say the barrier to entry is low, and yet the vast majority of petitions still don't reach the 100,000 th

Who knows what's going on behind the scenes, but as you say the barrier to entry is low, and yet the vast majority of petitions still don't reach the 100,000 threshhold, so that gives the Whitehouse some insight into peoples' priorities, at least among netizens. Also, I have heard that Congress has a rule of thumb - if more than three of their constituents take the time to write and mail an actual letter about the same topic, and they're not looney's but serious-minded people, that signals it's a real issue amongst their constituents and something that needs to be on their radar. I suspect this petition system works similarly.