Hi abraxis,
Sorry for the delay. Had a full day yesterday.
Yes, you can use either one. They were just two different options.
As for the new user, the Countif will capture the new input as I used the whole column reference.
=COUNTIF(
B:B,K2)
For the pivot table, you would need to take two actions.
1) Change the source data to include entire ranges
Analyze >> Data >> Change Data Source >> Sheet1!$A:$B
2) Once new data is loaded, you will need to right click the PT and select refresh
P.S. You could also look into a dynamic named range
How to Create a Pivot Table with Expanding Data Ranges -