Boots on the table. It's a common phrase, up there with "boys before toys" in the world of common wisdom for list building in 40k. You need boots on the table to hold objectives and avoid getting tabled. Some factions, like the Tau and Imperial Guard, have fragile boots that need a lot of protection. In other factions, like the various flavors of Space Marines, the boots are tough enough to be one of your best assets.
One thing I've never been sure of is how many "boots" does a vehicle count as? True, a vehicle can never hold an objective, but they can do lots of other thing boots can do. Vehicles can contest objectives, draw fire, and attack the enemy. For the more numerous factions, vehicles as boots might not enter the calculation, but for the elite and outnumbered forces, I think it can be worth discussing.
So, how many boots do you think each vehicle counts as? None? One? One per hull point? More or less? Discuss.