GS, I presume the sender meant "Been There, Done That" which he means hasn't been successful in his prior experience.
Off topic, I want to thank you for your efforts in Math Teach.
> "BTDT" ??? > Sorry to disappoint you, but I am NOT all-knowing as > you seem to assume. I do know "IMHO", and a couple > of others - but "BTDT" is unknown territory. > > It would be most useful for the comprehension of > others (certainly of the person to whom that "BTDT" > seems to be directed, namely, GSC) if you were to > explain such an anagram as the above at least the > first time that you use it in a message. Thanks. > > Perhaps ingestion, as fish food, of some of the > shrimp that you've been so very assiduously > purchasing may help you to understand this? > > GSC > ("Why Am I Not Surprised?")