Yes. Let's face it, if kpop groups just released a song then split kpop wouldn't have anywhere near the popularity it has.
Concepts are part of the reason why little fans get hyped for CBs. Seeing the styling, image teasers, clothes can build hype. Sometimes a concept denotes what a song and dance would be like so having an interesting theme to go along with a song can often affect, good or bad, how is perceived.