You wouldn't happen to understand: Froschkönig.com
I think it means FrogPrince, but not sure. Seems to be over 25,000 exact monthly searches (in Germany). Some firms even seem to have this name. What do you think?
If you have the funds, invest.
I think IDNs won't be popular until they're not shown normally in all popular browser address bars, nobody likes xn--something-something.com
But with German IDNs I think it's one of the safest ways to go, Germans like their umlauts and other special signs