Count unique entries based on two columns

Hrrm, difficult 1, I could not come up with a single cell solution (there may be one), so I used a helper column (C):
C2:

Formula:

=IF(COUNTIF($C$1:C1,IFERROR(SUMPRODUCT(MATCH(A2&"Yes",$A$2:$A$8&$B$2:$B$8,0)),"")),"",IFERROR(SUMPRODUCT(MATCH(A2&"Yes",$A$2:$A$8&$B$2:$B$8,0)),""))

then this to get the Count:

Formula:

=COUNT(C2:C8)

which returns 3

See attached

Hope this helps

welcome to the forum, gradient. another alternative is with array formulas:
=SUM(IF(FREQUENCY(IF(B2:B8="Yes",MATCH(A2:A8,A2:A8,0)),ROW(A2:A8)-ROW(A2)+1)>0,1))

...confirmed by pressing CTRL+SHIFT+ENTER to activate the array, not just ENTER. You will know the array is active when you see curly braces { } appear around your formula. If you do not CTRL+SHIFT+ENTER you will get an error or a clearly incorrect answer. Press F2 on that cell and try again.

if you need the unique names say in E2 downwards, then this array formula would help:
=LOOKUP("zzz",CHOOSE({1,2},"",INDEX($A$2:$A$10,MATCH(0,IF($B$2:$B$10="Yes",COUNTIF(E$1:E1,$A$2:$A$10)),0))))

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