I agree that most CTC black teas are good for only a single infusion.
However, I find that many whole-leaf (or as whole as possible) Chinese
black/red teas are good for at least two or three infusions. I am
currently finishing up some black rosettes I bought from Yunnan
Sourcing on ebay and they have staying power, most likely due to being
large/whole leaf and also due to being tied. Both aspects allow the
leaf to release its goodness slowly over several steepings. Plus, the
later steepings are often smoother and/or not as bitter as the first.

Alan