The Conduit sold 420.000
Madworld sold 510.000
These titles had very small marketing budgets compared to MHT.
Monster Hunter Tri sold 440.000 so far in the west.
It had a very large western marketing budget for a 3rd party Wii title, its marketing budget will probably only topped this gen on Wii by one game once it hits the west: Dragon Quest X.
Flop? No. Success? No. Mild disappointment? Probably.