I wouldn't worry about the implementation too much since, as you say, it is really very little code and easy for anyone to code up themselves. What is awesome

I wouldn't worry about the implementation too much since, as you say, it is really very little code and easy for anyone to code up themselves. What is awesome about what you've done is the idea and the interface. I'd focus on expanding that with more interesting use cases. For example it would be cool if this hooked more neatly into rails localization where I could say something like: = t('some_set_of_possible_stuff.*') Or whatever. I agree with the other poster who states it makes your app more hard to test however that is not a good enough reason to not do something by itself. It just means you need to be measured in how and where you do it and careful. In the right app, the value to the end user experience wrt personalization is super high so it is worth it.