Friends from school or for that matter, a real physical place of
meeting, is very different from the ones you make on the net. For
me internet friends only come together by that very same interest
of the virtual environment that you met each other, be it games or
some chat channel or what. Once that interest dies off, you find
very few other things to really sustain the friendship. Real life
friends are formed through long periods of being together in the
same physical space, and sometimes inevitably you will be forced to
experience many varied things together, and hence the bonding
between these friends will be stronger than those of the virtual
environment. You'd have more common collective memories and it'd be
easier for "real life" friends to do things together or sustain the
friendship, coz your friendship with these people are not just
bounded by one single interest. Thats just IMO, haha.
Internet friendship, except in some cases, tend to be rather
frivolous and fragile, and often rather superficial.