carpet-bombing
noun /ˈkɑːpɪt bɒmɪŋ/
  /ˈkɑːrpɪt bɑːmɪŋ/
[uncountable]- the act of dropping a large number of bombs onto every part of an area
- the carpet-bombing of towns and cities
 
 - (business) the act of sending an advertisement to a very large number of people, especially by email 
- The product launch was preceded by a publicity carpet-bombing campaign.