Ooh, we have a solution to that problem (losing interest in collecting it if it's fully automated). Assuming you're collecting data that you want to change, like, for many people, their weight, or, say, how much time you spend on Hacker News: http://beeminder.com/d/hn

Namely, set up a commitment device that forces you to keep your datapoints on a path to some goal. That's what Beeminder does.