I did the math and at Level 8 you get from 1 mark 1.04 Ad which breaks the flat 0.95, but the point is justifying in which can be used.. Maybe on 
since you don't tend to fight much until you get your 
..which is around Level 9 or 10.
McSatan2 votesNo, Getting +9 AD to your 60AD is far more valuable than getting +20 AD to your 400 AD.
Mannysmoker1 votesYea, i though it, outside of bruisers i don't find any other reason you justify those runes being equipped...
Kouga1 votesGenerally players get flat AD marks because it helps more with last hitting (more early AD = easier to kill minions) and helps with early trades/harassment. Usually by the time the scaling marks give you more AD, the difference between you and your opponents will probably be more than the couple extra AD you're getting, so it makes less of a difference later on. If you're ahead, you don't need the extra. If you're behind, the extra 0.1 AD per mark probably isn't going to save you.
Mannysmoker1 votesYea, it can backfire really hard on your lane, making trade off flat Ad vs your lane opponent can be significantly huge..
Kouga1 votesArmor penetration marks, however, used to be a popular choice for AD Champs who prefer the late-game damage over the early game power. That might be worth looking into.
Mannysmoker1 votesMaybe on 
since the have a raw damage early..
Mimy1 votesI must really play Koggy differently xD