1. What does it mean?
스밍 is a clipped form of 스트리밍. Fans use it when listening to or watching content online, sometimes in the context of supporting a release. It can describe ordinary streaming without implying an organized campaign.
Also written or said as 스트리밍, seuming
2. The nuance
It is not the same as buying a download or owning a file. Whether a play counts toward a chart depends on that service's rules, not the slang term.
3. Examples
“출근길에 새 앨범 스밍하면서 갔어.”
I streamed the new album on my way to work.
“스밍으로 먼저 듣고 마음에 드는 곡을 골랐어.”
I streamed it first and picked the tracks I liked.
Sources
References support the meaning and usage. Example sentences are written for NoCapWiki.