Alan, who runs a Londis News Extra store in Attleborough, Norfolk, donned the outfit in a repeat of last year's National Independents Day activity, when he dressed up as the Star Wars character to draw attention to his store.
When he addressed the delegates - without his mask - Alan said: "People rush in and out of our store, when what we want them to do is to hang around. If they see Noddy and Big Ears or Darth Vader in there, it doesn't matter how busy they are, they'll stop to ask you what's going on."
While admitting that dressing up is not everyone's cup of tea, Alan pointed out that you have to do whatever it takes to attract shoppers away from the multiples.
He said: "Whatever you do, you have to be comfortable with it and be committed to it.
"It's time that independents began to create their own identity. Campaigns like My Shop is Your Shop and National Independents Day are a great first step, and we need to promote them to more and more quality retailers."