The “We the People” petition tool created by the White House has certainly been popular. It hasn't been effective, since it hasn't actually resulted in any serious changes or any issues being addressed.Well, it did get the White House to publish its secret beer recipe, but that's probably not what the Founding Fathers had in mind when they created the US constitution.
Yet, it has been popular with petitions like the one to build a Death Star or deport certain British journalists. People seem to be pleased with it as it is, perhaps the illusion of some control over what their country does is good enough.
Whatever the case, its popularity has surprised the White House, so much so that it's now raising the threshold at which it has to answer to any petition from 25,000 votes to 100,000 votes, all of them in 30 days.
Note that the White House only has to answer to the petition, i.e. just talk about, not actually do something.
It does make some sense, a number of trivial petitions have been filled and, while fun, they take time that could be used for more serious issues. Still, all it does is give Reddit a bigger challenge.