We should not confuse yields with loadfactors. You can get 100% loadfactors if you offer all your seats at Rs. 1/- per seat. Spicejet does seem to have industry leading load factors - what is not clear to me is their yields. Are they on par with the industry (in which case the load factors are impressive)? If the load factors are at the cost of yields, then that is a whole different story.

The LCCs in India still puzzle me. In the US, when WN pursued the low cost model, it used secondary airports where the airport fee were lower and cost models were different with employee stock options, no defined benefits pensions, etc. It is not clear to me what edge Spicejet or AirDeccan has on the cost side. Air Deccan at least uses non fare revenues to bolster revenue but Spicejet does not seem to have any other significant revenue sources besides fares.