The Ratchet and Clank franchise took a dive sales-wise in the second half of the 7th gen, Even A Crack in Time underperformed being the first in the franchise to fall short of 2 million (according to VGC). So I guess that sets a benchmark for R&C, if it gets over 2 million it's given the franchise a boost.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix