Any website who sells the items they review, or who carries advertisements related to its content will be at risk of the advertiser influencing the site's content directly, indirectly or subliminally. Such a website and its reviews are, therefore, not independent due to this conflict of interest.
As it was put on another website (see https://www.gentlemansgazette.com/gentleman-dress-suit-budget-15-tips-guide/ Accessed 16 January 2020):
We do not sell or advertise what we review on this website.
We avoid conflicts of interest.