how phrases sell soap

Those old television commercials always had the best taglines. I think my all-time favorite is from a black-and-white cartoon commercial for Tide circa 1955: 

              Nothing else will wash as clean as Tide, 

       yet is so mild.

The tagline gives the consumer everything she needs. She wants her clothes to be clean, of course. That's her top criterion in selecting a detergent. So the tagline addresses her concern right off the bat. 

             Nothing else will wash as clean as Tide . . .

The words roll off the tongue with a spring-like freshness. Then to address her secondary concern – she refuses to sacrifice delicacy for cleaning power – the tagline gently counters:

       . . . yet is so mild.

The phrase has an Eastern rhythm. She really feels the word mild. And she feels reassured.