Sale promotion was not discounted for buyer, Buy 1 Get 1 at 20% Off

[warrenwren]

Last weekend, I ran a "Buy 1 Get 1 at 20% Off" promotion, using Promotion Manager in my store admin area. The promotion has ended now. But I had one buyer, who purchased several items, in two groups (Group one had two items, about $ 17 each;  Group two had 5 items, $13, $19, $2, $2, $2.) The Promotion Manager reports the total of all items as "promotion sales." However, the Sales Record shows only 2 or 3 cents Off of the lowest priced items. The PayPal transactions show that the buyer paid the amount shown in the sales record. Since the total sales value was around $70, I would have expected discount value on the 'second' items to be around $ 7.  Perhaps the customer and I misunderstood how "BOGO at 20%" is supposed to work. In any case, I included a few "bonus" items to satisfy myself that the buyer got the deserved discount. 

What am I missing?

Thank you, warrenwren

[penguins_dont_fly · Accepted solution]

The discount will always be applied on the lower priced item.

If the buyer paid separately ...

<Group one had two items, about $ 17 each>

Should have applied 20% off of the second $17 item ... ($3.40)

<Group two had 5 items, $13, $19, $2, $2, $2>

Should have had 2 items 20% offs 

$13 with $2 as the second item (0.40)

and $19 with $2 as the second item (0.40)