thecages

Mieke may have independently coined a phrase: slogo
Does it count if the phrase is already documented elsewhere, but you didn't know this when first using it?

slogo noun. A slogan/logo. Corporate slogans that are "logo-like" in that they are used repeatedly in ads and other media. Nike's "Just Do It" is a classic example.

Another prominent example is the ubiquotous McDonald's 'I'm loving it!'.