Reinforce your message
"Why should we keep that thing there? It's already at the sidebar/body/somewhere else..."
This is my favourite of client's recurring questions. They all fear something is wrong when repeated. Probably driven by some obscure space scarcity fear they tend to identify those repeated items as threats to its siblings.
Placing something more than once in an interface you create diferent relative weights in terms of business relevance. Scarcity of space is a fact, but scarcity of attention is a psychological asset we should use for our convenience.
What is the most important thing for your business?. Answer that and make sure it's visible enough upon the rest.
