Once you have done so, it's time to wipe that slate clean once and for all.

CNN: Feel the relief of a Facebook purge

The company must spend to maintain its plumbing and constantly improve its interface, but once that's done, it stands back and collects its middleman money.

WSJ: Is Twitter Really Worth $10 Billion?

As the political commentators discovered once again this year, it's analysis done before the election that's very likely to make you look foolish.

CNN: Our subtleties explained

Once the fishing method of choice, these days it's generally done for tourists.

WSJ: Cormorant Fishing in Yunnan Province, China

Once you're done with the hotel bar scene, it's time to put on your dancing shoes.

CNN: The hottest clubs and bars in Miami

Personally, I've only been tested once this year, but you can quite easily get done anything from three to eight times a year - it's just the luck of the draw.

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