Hmmm, someone has their grumpy head on, today
IMHO money has been the cause of more breakups of friendships than perhaps any other single cause.
I know people, who I would call friends, that I haven't seen or called for years. Every time we meet up, it's like the intervening time just never happened, as we carry on right where we left off. These are people who are more than just mere acquaintances.
I've also had friends from the Internet. One such "pen-pal" had been corresponding with me for about six years before we finally met (nearly two years ago), and we've never seen each other again. We got on in person just as well as we did in correspondance. Sometimes there will be months pass, where we are out of contact, since we both travel a lot. This doesn't diminish the strength of our friendship, though.
That having been said, I would say that I can count my "true" friends on one hand, and I've met them all. As someone earlier commented, there are degrees of friendshhip and trust.
I would suggest that all the comments on this thread have contributed to the topic...