Heres a quote from Pillbox on another thread

Remember all , that this is not a manual Yo Yo Sale (unless there are some serious glitches this week) but a fully automated Yo Yo Promo.
The Worlds First, the programming has been difficult so has the integration of the algorithms’ graphs and graphics.
So the manual Yo Yos held previously are as described by members in the posts above.
BUT the New automated Yo Yo Functionality works like this
1. Max and min discount parameters will be set.
2. Each product will Yo Yo independently within its own algorithm based on the Min-Max parameters, this means Product 1 might be at a 15% discount yet Product 2 is at 39%.
3. The Users Yo Yo session starts once the first product is added to the basket, at this point a countdown clock appears with 30 minutes on it, this will countdown in real time.
4. At the 3 minute to go point on the clock a Claxton sounds letting you know you need to move to checkout, if you don’t and the clock goes to zero your basket reverts to full price. You will then need to empty it and start another Yo Yo session.
5. If you proceed to checkout , the clock re-starts at 15mins and gives you this amount of time to check out.
It’s going to be exciting I think