Determing the ratio of buyers who take up a multi-buy offer (i.e. redemption rate)

Hi,

My question is how do i dtermine the % of shoppers who took up a multi buy offer.

So for example the product normally retails for $4.60

and the offer was buy 2 for $6.00 so if EVERYONE takes up the offer the sell price will be $2.99 right?

But not everyone takes up the offer (some ppl prefer to just buy the one unit instead of two). In my data the average sell price for the week of the multi-buy promotion was $3.86

So how do i figure out the % of sales that were made were shoppers took up the multi-buy?

Thanks!

Re: Determing the ratio of buyers who take up a multi-buy offer (i.e. redemption rate