The idea is thus. To have an extra button next to the votes called the 'Nudge button'. This is a counter, reset every week, that anyone can click in that time even if they've already voted. And the next week they can click it again. The idea is to track popularity over time to compliment the overall total popularity and give the giffgaff Labs team insight into what ideas should be prioritized.
Another scenario is for user experience. I recently was looking for an idea, I found it but had it had no feedback on its status or progress other than a total vote count an a 'we're looking into it' sticker. Myself as a user I was left with nowhere further to go and no answer to my search. What I might have liked is a nudge button to tell giffgaff that although I'd already voted on the idea I'd quite like to know how it's getting on. While not answering my questions does give me an action that I can carry out to find out more.
Once a week, fortnight or month the highest nudged ideas for that period are followed up on and their status updated. This also gives the Labs team some extra analytics when proposing an idea in meetings in sentiment over time, which can be presented in a pretty graph if it's good!