"Boycott Black Friday"?
Unless you're ready to violently overthrow an oppressive institution (The only way any REAL change has been brought about throughout history. I'm not advocating violence but when you are not protected equally under the law, those who administer the law must be removed.) - your collective pennies have little power to accomplish anything at all.
Unless you are planning on using the money you would have spent on creating wealth, goods or services - your pennies are better off with those who will not continue to be subjugated members of a debt-ridden consumer class.
Unless you are willing to spend the money you would have saved on that new flatscreen you've been eyeballin' at a Black-owned business - your pennies are worthless.
Unless you are willing to use the money you would have saved on the improvement of your credit, paying off of bills, having a savings account and investing in your children's futures - your pennies will remain pennies for another generation.
Unless you are collectively using that savings (Which you won't - those low-priced Beats By Dre at Target are just too irresistible.) to create better institutions which better serve your own communities - your pennies are not even worth their weight in copper.
Unless you are willing to use the money you would have spent on helping people you actually know - your pennies can stay in your pockets.
Unless you are going to do more than boycott - BOY, STFU and become a man.