21st Century music marketing: Release a new single Selena Gomez & Taylor Swift keys to succes Pulchritude still sells

Selena Gomez' Round & Round fell to #3 from #1 on Radio Disney this week. Gomez is an ideal 21st Century music marketer, like her equally as talented contemporary, Taylor Swift. Just this week Gomez released a new single, Year Without Rain.

Swift does the same; as soon as one single fizzles, have another in the wings. Britney Spears used to use that tactic. Even The Beatles and Elvis Presley, so it is nothing new.

Lastly, I need to know what this trend of photographs in videos is? Thought everyone was viewing them on SmartPhones today.