That's always been there in music, sometimes in a double entendre form. In Tutti Frutti, Little Richard is bragging about the girls (Sue & Daisy) he got. The Beach Boys' Little Deuce Coupe is about what their car does. There's also an old blues song called I'm The Fixer by Willie Mabon.

Money, that's what I want.

It's been part of blues, R&B and small-r rock music since the beginning.

[Edited 1/5/21 9:20am]

I think videos just made the visual more desirable, meaning more people desired the image. When it was just radio/audio a certain amount of fantasy/imagination is needed. People dressed like Prince, MJ, Madonna in the 80s when video was new.

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With modern music in the age of Spotify and Instagram and all the other odd ways new music is delivered it can be hard to tell the song from the advertisement or if the song is the advertisement. An artist posted an interesting stat on social media that a $1 album purchase on Bandcamp is equal to that album being streamed 331 times on a streaming service. Seems a rough way to generate income. I'm not surprised many modern "artists" use these influencer tactics to make coin.

You can definitely see a shift from "niche concern" to "only concern" with the impact of Reagonomics.

funkbabyandthebabysitters said:

It's more so in the last ten years Thank reality TV and hip.hop

I think I know what you mean, yeah, I'd say so, swag culture got prominence late 00's-early 10's maybe. It's a bit different to shills like wu tang and chamillionaire spruiking products, now a lot of mainstreamers are obsessed with identity politics, being social media influencers and making their fanbases into cults, so we get too many hoe shows and thot beats. Fela Kuti did say music is the weapon.

Self-promotion has always been around but in the modern age it's on steroids.