This simple answer is "It depends" @archiryan There are some security features I feel are essential like a secure website and SSL certificate. When it comes to things like Trustmark, Norton Shopping Guarantee or some other thing I'd say "It matters if it matters to you and/or your website visitors."
I once had a customer that decide not to use my web design service because she proclaimed "How could you be any good if you don't have a BBB rating?" In real life some people only buy a certain soda, only shop at a certain store or only drive a certain car. I don't personally go after customers who shop specific trusted environments but if I did I'd make sure that my website had all the markings and information needed. Does that help any?
roy darling *my posts seem a lot shorter in my head