The basic idea can definitely be implemented in more sophisticated ways, though I'm not sure how quickly one would hit the point of diminishing returns.

At this point I think there's a clear advantage to having everyone using the same database; more feedback in the same place means we'll more quickly figure out how good the horoscopes are, so that the horoscope-choosing script is better calibrated and we have the data we need to know what kind of horoscopes we need to write more of.

The code as written does allow for several tumblrs to draw from and report to the same database, so if there's an advantage to having different people see different horoscopes even though each group has the same probability of seeing any given one, that can be implemented easily enough, but I'm not sure that's the case.