How often should one sweep?

So what is the consensus on how often (in terms of chords burned) chimneys should be swept?
There are a lot of factors that contribute to build up but lets assume that on average the wood being burned is almost as seasoned as it should be (some is dry, some is a little wet), the user brings the internal stove pipe temp up to 500°F once daily to loosen stuff up, and the chimney is well insulated.

I'm guessing it would vary depending on an old stove or a clean burning stove.

Depending on how easy it is for you to sweep it, I would do it frequently (twice a month or better yet, once a week) for awhile under different burning conditions to see how much creosote, if any, your stove produces. Then put together a cleaning strategy that you're comfortable with.

If it's a real pain, or if you have to pay someone to do it, then I would wait until the end of the heating season to check it out, but I would pay extra special attention to how the stove operates in the meantime. If you start getting a lot of creosote forming in the firebox or if you start getting smoke in your face, then it's probably time to check the chimney. Also, if you have a cleanout, you can easily keep an eye on creosote formation with a mirror and by analyzing what's dropped into the cleanout.

I'm thinking about sweeping mine again this weeekend. Its a real pain to do so Ill probably just get an idea, this weekend, of what its like after a 2 weeks of burning and then judge from there. Hopefuly I'll be able to do it once a season if I'm lucky!