How to combine values from multiple rows into a single row in Excel?

I have a data dump in Excel that consists of annual customer data for two different values. The data was provided with a separate row for value for every year and customer. I.e. it looks like this:

I'm stuck with a row for Customer 1 for Value A in 2009 and a separate row for Value B for the same customer in the same year.

In some instances there is no Value A or Value B. In the example above, you can see that Customer 1 has no Value B in 2011, so no row was generated for that. And, though not represented in the example, some clients will have no data for either value in a year (and thus no row for that customer in that year). In that situation, lacking a row for that customer in that year is fine.

I want to get this into a worksheet where there's one row for both values for every year and customer. I.e., I want the data to look like this:

What is the most effective way to create that result?

This is VBA, or a macro you can run on your sheet. You must hit alt+F11 to bring up the Visual Basic for Application prompt, go to your workbook and right click - insert - module and paste this code in there. You can then run the module from within VBA by pressing F5. This macro is named "test"

Sub test()
'define variables
Dim RowNum as long, LastRow As long
'turn off screen updating
Application.ScreenUpdating = False
'start below titles and make full selection of data
RowNum = 2
LastRow = Cells.SpecialCells(xlCellTypeLastCell).Row
Range("A2", Cells(LastRow, 4)).Select
'For loop for all rows in selection with cells
For Each Row In Selection
    With Cells
    'if customer name matches
    If Cells(RowNum, 1) = Cells(RowNum + 1, 1) Then
        'and if customer year matches
        If Cells(RowNum, 4) = Cells(RowNum + 1, 4) Then
            'move attribute 2 up next to attribute 1 and delete empty line
            Cells(RowNum + 1, 3).Copy Destination:=Cells(RowNum, 3)
            Rows(RowNum + 1).EntireRow.Delete
        End If
     End If
    End With
'increase rownum for next test
RowNum = RowNum + 1
Next Row
'turn on screen updating
Application.ScreenUpdating = True

End Sub

This will run through a sorted spreadsheet and combine consecutive rows that match both the customer and the year and delete the now empty row. The spreadsheet must be sorted the way you've presented it, customers and years ascending, this particular macro won't look beyond consecutive rows.

Edit - it's entirely possible my with statement is completely unneeded, but it's not hurting anyone..

REVISITED 02/28/14

Someone used this answer in another question and when I went back I thought this VBA poor. I've redone it -

Sub CombineRowsRevisited()

Dim c As Range
Dim i As Integer

For Each c In Range("A2", Cells(Cells.SpecialCells(xlCellTypeLastCell).Row, 1))
If c = c.Offset(1) And c.Offset(,4) = c.Offset(1,4) Then
            c.Offset(,3) = c.Offset(1,3)
            c.Offset(1).EntireRow.Delete
End If

Next

End Sub

Revisited 05/04/16

Asked again How to combine values from multiple rows into a single row? Have a module, but need the variables explaining and again, it's pretty poor.

Sub CombineRowsRevisitedAgain()
    Dim myCell As Range
    Dim lastRow As Long
    lastRow = Cells(Rows.Count, "A").End(xlUp).Row

    For Each myCell In Range(Cells("A2"), Cells(lastRow, 1))
        If (myCell = myCell.Offset(1)) And (myCell.Offset(0, 4) = myCell.Offset(1, 4)) Then
            myCell.Offset(0, 3) = myCell.Offset(1, 3)
            myCell.Offset(1).EntireRow.Delete
        End If
    Next
End Sub

However, depending on the problem, it might be better to step -1 on a row number so nothing gets skipped.

Sub CombineRowsRevisitedStep()
    Dim currentRow As Long
    Dim lastRow As Long
    lastRow = Cells(Rows.Count, 1).End(xlUp).Row

    For currentRow = lastRow To 2 Step -1
        If Cells(currentRow, 1) = Cells(currentRow - 1, 1) And _
        Cells(currentRow, 4) = Cells(currentRow - 1, 4) Then
            Cells(currentRow - 1, 3) = Cells(currentRow, 3)
            Rows(currentRow).EntireRow.Delete
        End If
    Next

End Sub

Another option:

1. Select Column B, press CTRL+G -> Special-> Blanks -> OK
2. Type = press ↑, then CTRL+ENTER
3. Select Column C, press CTRL+G -> Special-> Blanks -> OK
4. Type =IF( press ← type = press ← press ↓ type , press ↓ type ,0) then CTRL+ENTER
5. Select all data and Copy and Paste Special as Values
6. Remove duplicates.

EDIT:

Explanation: I am trying to make use of GoTo Blanks option. Once you have selected blanks then you can enter the same formula for all selected blank cells. Regarding OP's question, the data looks like have consistent blanks, i.e.: Value A column blanks have the same CustomerID as above nonblank row. In the same way Value B column blanks have the same CustomerID as below nonblank row.