The authors examine how new brand entries affect consumers' considerat
ion sets. A within-subject longitudinal experiment examines several en
try positions into existing markets. The results suggest that new bran
d entries produce changes in consideration sets toward dominating, com
promise, and assimilated brands, away from extreme brands in two-brand
markets, and toward dominating and away from extreme brands in eight-
brand markets. These results are confirmed by a second experiment that
utilizes a between-subject design and markets with six existing brand
s.