I got my first Keurig when you could only get them online. No one carried them much less had a clue what a K-cup was!
It finally died and this one I got at Target. I'm sure they are all the same, but a friend of mine said that if you buy direct from Keurig, IF something wears out, they will replace it. I didn't know that, but as I said, mine was several years old.
Personally, I would not order the k-cups from Keurig. Well, again, now you can get them everywhere. But I was a 'platinum' member and realized as soon as I hit the 'place order' button I had made a mistake. Called customer service literally within 5 minutes and was told too bad, so sad. On the occasion I do order online instead of just pick up in a local retail market I go to Green Mountain which still has a wonderful selection and much better customer service.