In any network it is very easy to assume that everyone is alike. At a very least most networks (and especially online communities) assume that the participants each have a set of things in common, over time these grow to include generally a specialized vocabulary and a shared worldview. The danger that this holds can be seen as you observe how networks change and grow over time, the more complex the shared history, the harder it can be for new members to join and once joined, it is that much harder for the new members to influence and shape the network.

But writing, talking, even contributing money, is a different act than voting. Voting is irrevocable and is, most of the time at least, a representation of making a decision - this candidate or the other (at least here in the US we don't generally have vote off style elections where you indicate a level of support and second/third choices etc, our voting tends to be either/or votes). To get people to vote requires a number of specific and each slightly difficult steps.