I think I actually live in fear of yarn vendors closing shop before I have managed to buy their yarn. There is a level of panic when I see yarn I like of it not being there when I come back. Probably this is partly from the quest to own Vesper Sock Yarn or Brooklyn Yarns or Sundara - all of which I have actually managed to buy but not necessarily in the colourways I most wanted.
We really don't have very many yarn stores here in my city. We have Spotlight. If you are prepared to drive, there's a Lincraft left somewhere here. And there's possibly 3 dedicated small yarn stores I can think of - I've only actually been to 2. These are still very much aimed at the grandma type knitter; I have not seen much in the way of "young" colourways and yarns.
So I don't get to see and touch and enjoy the types of yarns I can see on the internet in person. And so, sometimes it's hit and miss when I order things. And that's okay because *someone* will like the skein as socks! And half the time I'm finding people bag'sing them anyway. And that's okay too - maybe because I'm a process knitter - I don't mind because I get to knit with the colourway and see how it turns out and then I gift it and it's like a two for one deal.
Some yarns are nontradable. Some I have bought specifically for me and no matter what, you can't have them. I buy Socks that Rock for me but seem more happy to gift those socks away than a lot of the yarns from smaller outlets I buy from (except for Ruby Slippers and Lemongrass - mine mine mine) . Maybe I just have more favourite colours than others.
But even with larger sellers, I still have this urgency of what if they close down and I never got that skein? Like Lisa Souza for example. And I ogle the certain colourways that I have my eye on and I hope the site will still be there when I come back later. Somehow, I guess, I'd rather buy all my future yarn purchases now and have them at home in the cupboard than never have them at all!