It is a fun idea for a thread, although tough to answer. I suspect we all have had names in some extensions without sales. Also, keep in mind that in new gTLD the match across the dot is more important than the actual extension itself.
First to follow being positive (contrary to thread title
) but
the global TLD which has been best for me is .org. I have put so little work into researching them, have never had more than 5 at a time, never paid more than reg fee or equivalent, never really promoted any, but it is my best ratio of returns to price.
.Space and .icu have also been a nice ratio of clearly positive for me, with multiple sales, although only a few $$$+.
Worst?
If I measure that as the worst ratio of return vs money invested (and discount the ones with a handful of registrations but 0 sales)
it is actually .com. I am hoping that will change, but as of now that is my personal experience.
If worse is measured as the most registrations without a sale it would be .best or .gdn, but in neither case did I sink a ton of money in the extension.
For .best I still hold out hope I will get sales, as they make nice domain phrases, the standard renewal has recently dropped, and the launch of The.Best social network will increase visibility.
I have let almost all of my
.top expire, but although I had a few low value sales I have registered a bunch without inquiries in the past. I think it is hard to sell unless you are China based.
My .xyz experience sort of the same. A low value sale but no real end use interest.
Others that I have held not a lot but have not had sales or inquiries are .info and .pro. Trying to decide whether to renew or not on a few one word ones right now. I have not had a sale yet in .one, but with great words I definitely see worth in the TLD.
Bob