Logos are not branding-- they are a piece of it-- they are a visible mark that instantly triggers a person's thoughts towards your work-- ("instantly" for them-- constant effort on your part with a lot of exposure to your target audience) To work well a logo should be simple, recognizable without reading, good in a single color (black and others). You should have something that works in a square/circle and also horizontal. They don't need to tell the whole story, there are other ways and means to do that.
Logos do not have to be static. Look at Google, they play with their logo on a regular basis-- part of their branding.
Logos don't have to follow the rules... but if you choose to ignore, step up the exposure they get and they will work.
Logos don't have to be pretty... logos are not a piece of art for the living room, they are a component of your vision to make something happen... There are some mighty ugly logos out there that are recognized before you can blink. And that IS their job!
"You Deserve a Break Today" & "I'm Lovin It" are TAG LINES
"Ronald McDonald" is a mascot
"The Golden Arches" drumroll please- Is The LOGO
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