Depending on the foot traffic, how you look after them, and how aggressive your
feet wiping is, the dontbeadoormat design will fade over time. It is best to pop
them on a sheltered doorstep with minimal rain or UV light (coir mats lap that up!) 
It's also best that you love your dontbeadoormat almost as much as your first
born / fur baby / fave house plant. Every now and then your dontbeadoormat
might need a wee shake, pat on the backside or vacuum to keep it as looking
as slick as poss.