Usage patterns
〈人〉の間で人気だto be popular among (a group of people)
This singer is popular among young people.
買い人気が強いbuying sentiment is strong (market context)
Buying sentiment for that stock is strong, and its price keeps rising.
人気が高いto enjoy high popularity
This product is very popular overseas too.
人気が落ちるfor popularity to decline
That show's popularity has been declining recently.
人気を博すto win widespread popularity (formal)
That movie won popularity all over the world.
Expressions
人気を呼ぶcapture public interest; enjoy popularity 人気をさらうsteal the show; capture all the popularity; upstage 人気を集めるgain popularity; attract attention; become popular