For newspaper stands, they could be relatively close, as customers are often on foot and unlikely to walk more than block or two.
Other tactics can involve delaying introduction of some versions of certain products since it can also save some companies money.
Self-competition is a common side-effect of mergers and acquisitions, as the new combined business often has similar products and nearby retail locations.
The success of the business often depends on their ability to eliminate similar products and redundant retail locations.
In the case of General Motors, they were eventually forced to drop their entire Oldsmobile line, as it was largely redundant with Buick, and to a smaller extent Chevrolet, though Pontiac which also later got axed as well had a sporty flare to it which made it look less redundant.