Conversation so far:
What was Westlife's debut album?
Westlife's first album, simply titled Westlife, was released in November 1999
Did Westlife's first album Westlife do well?
Westlife's first album Westlife went to No. 2 in the UK and their first No. 1 in Ireland.
How many records did Westlife sell of their first album Westlife?
Westlife's album Westlife became the eighth best-selling album of 1999 in the United Kingdom, and ended up being certified 4× Platinum.
What was Coast to Coast ?
Coast to Coast is the second studio album by Irish boy band Westlife.

Question: how many records did it sell?
Self-contained rewrite: How many records did Westlife sell of Coast to Coast?