Hey Chris
Funny that I stumbled on your post. I will reach out on LinkedIn.
Amazon price reference seem to be based on the average selling price and a reference (ceiling price).
Only if sufficient volume has been sold at the reference ceiling price, will that be displayed as a cross out. Otherwise an average price, or sometimes no reference price is displayed. You can see the average price by clicking on the SKU in your manage inventory and you'll see historical 30 day sales averages.
The only reference period as I am led to believe is the last rolling 30 days. Anything beyond that is not in the calculation.
The reason I stumbled on your post was a more complex issue regarding the referral fees, subsequent reference pricing, and deal mechanics of the various discount models. Will drop my understanding below, but feel free to correct it if you have a better understanding. Some of this might be helpful too.
1. Deal (Lightning or Top Deal)
Referral fee is based off the actual selling price during the deal
Sales made at this price do not count in the future average selling price mechanic, and seen as "promotional sales". Therefore in theory, if you sell 100 @ £39.99 before the deal hits, then sell 1,000 @ £29.99 during the "top deal", the reference price remains at £39.99 and future promotions are not impacted.
Downside, is these are chargeable and Amazon can dictate what price you go at.
2. Voucher
Voucher is a full cost reduction and in the example, you would pay £10 to provide £10 off the selling price. Therefore offering a £39.99 with a £10.00 voucher, you pay referral fees on the original RRP (was price) and provide a £10 funding per unit + voucher fee.
Similar to the Deal mechanics, but more advantageous than the deal mechanic for referencing. These sales actually go towards "full price" sales in your reference period. So help build a reference price for future promotions.
So cost more to do, but can be a tool to drive initial sale momentum.
3. Price Discount (new tool)
This seems to be a very unattractive option. But I am yet to understand the full mechanic. Its a nice shiny tool and easy to use, but the cost implications are dire.
Amazon charge a referral fee on the "was" price. Regardless of the actual selling price. Therefore even though the sale was made at £29.99, the referral fee will be based on £39.99. You essentially give Amazon the £10 in funding.
As these are essentially just "price downs", the sales made on these deals are mixed in with normal sales. I.e. you sell 100 @ £39.99 before the deal, and £1000 @ £29.99 during the deal, your average selling price will get reduced. When you come to run another campaign, the average selling price of £30.89 will mean that your next deal will probably have to reduce to £24.99 or lower. (Self fulfilling prophecy). Alternatively, you have to hold off any tactical activity for the 30 day period and build up a new reference price.
I am doing some tests on the above assumption and will let you know.
Now do these get extra exposure, better promotional badging or other emphasis? I dont know. However, given that these are just price downs, it would be far more cost effective to just override your price for certain periods of time in your manage inventory page. This would result in the same exposure, saving message - but cost less given the referral fee is now based on the selling price.
Hope all is well anyways
Chris
-