user: Question: What is the sales when the artist is kelly clarkson?
Columns: ['Rank', 'Artist', 'Album', 'Peak position', 'Sales', 'Certification']
Types: ['real', 'text', 'text', 'text', 'real', 'text']
Sample row: [1.0, 'Bon Jovi', 'Lost Highway', '1', 300000.0, '3x Platinum']
SQL:

assistant: SELECT "Sales" FROM "Table" WHERE "Artist" = 'kelly clarkson';