In the Atlanta Journal/Constitution - there are various catagories such as "Happy Ads - Personal Interest - Massage etc... I suspect the ads you mentioned fall under the catagory of a "Happy Ad". I can only speculate that these ads (Have a Nice Day!) may be "filler". Other times, companies do take out ads simply saying "XYZ Co. has many jobs - apply today" - just to keep the company at the forefront of your mind.
Of course, these ads may be alien code designed to be interpretted only by other aliens currently living in and around your area.
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