Transposition of column values into rows based on a value criteria

Question

I have the following Excel spreadsheet:

        A             B           C         D            E       F       G
1                    Sale 1     Sale 2    Sale 3
2    Product A           0       150       400                 Sale 2  Sale 3
3    Product B       1.000         0       300         Sale 1          Sale 3
4    Product C          50        200       70         Sale 1  Sale 2  Sale 3
5    Product D         800          0        0         Sale 1

In Columns B:D you can see the Sales for each product.

In Columns E:G I want to show in which Sale the product was sold. Therefore, the Sale which is <> 0 should be shown.

So far used this formula:

=INDEX($B$1:$D$1,MATCH(TRUE,INDEX($B2:$D2<>0,),0))

but it only works if a product is sold only once (unique). Once the product appears in more sales as for example Product A this formula gives me only back the Sale 2 but it leaves out the Sale 3.

Is there a way to list each sale next to the product. Something like htis:

Transposition IF value <>0

Answer 1

In E2 and copied across and down to suit:

=IF(B2>0,B$1,"")

B2 is not anchored so will adjust to C2 etc when copied across (and B3 etc when copied down - equivalent to RC[-3]) whereas the row for B$1 is anchored so will not change (but the column will change in line with that for B2 ).