Do you count a fold as an "out"?

[SlackerMcFly]

Hypothetically, you have 8 outs after the flop and are HU against a LAGish player after everyone else folds. He has you covered by 100 chips. Villain bets an amount that worries but doesn't scare you.

Are you ~18% to improve your <open straight> name your poison here.

Or, are you ~20% factoring in the 9th "out" you might gain by pushing and/or betting an amount that you are mildly confident that will induce a fold by the villain?

Would it make any difference at all if on the bubble or early in the game to you?

I can't say why this came up, and I don't have a picture of a rabbit with a looter on his head. Just curious if this is a factor in your thinking.

Shalacka