Let me start up front by admitting my grammar isn't the best. Apparently, it's not the worst, either. The downside of being an English major is that the littlest things can drive you insane. I know there are accepted informal usages, but I hate it when they're used in formal communications.
In the parking garage at the building where I work, blazed in three-foot-high block letters, is the warning "Drive Slow." My first thought when I saw it was that it must be a cost saving measure. I could hear the boardroom exchange.
"Jim, we're having problems with people speeding in the parking garage. I think we should post warnings...something like 'Drive Slowly'".
"I'm sorry, Dave, but we don't have room in the budget for adverbs. You'll have to come up with a workaround. Could you get by with an adjective?"
Don't even get me started on advertising.