Is it a leak to bet less than half the pot?

At 10NL, I see this all the time. I can understand if you throw in .10 in a .30 pot but in 1.60 pots postflop I see .50 bets. I am pretty sure this is a leak but can someone explain why it is?

Also how do you treat min bets especially in raised pots? I see those less at 10NL but at 2NL I treated those same as checks.

It's not a leak if the bettor is betting with the nuts on a board that might scare off any players if he bets too high, but is hoping to get a call or a raise from hands that may have hit the board.

It is a leak if the bettor is bet-sizing his hands according to the BB.

Yeah, definitely not a leak. Bet-sizing is all about maximizing your expectation. Sometimes a smaller bet will do that, sometimes a larger bet will. Multiply the size of the bet by the percentage you estimate the opponent will call to find your expectation.

I use a few lines that employ a smaller than 1/2 pot bet on the river, as this is a bet many villains will call wit a very very wide range.

It's not about individual bets. It's about how particular bets relate to your (or your opponants') betting pattern. Both their long-term betting pattern and their recent betting pattern.

It depends on what you're trying to accomplish with the bet. Often times a smaller bet is best, because your opponent may not call a larger bet. Also, a smaller bet is often the best option if you're trying to entice your opponent to raise. Weak bets are seen as weak plays, and frequently people will attempt to raise you off of a hand if you make a weak lead.

I would only say it's a leak if there is a open ended strght or flush draw after the flop. If you don't make it atleast 1/2 the pot, the villain is getting the right pot odds to chase.

If your opponents will fold to a small bet, then it's clearly not a leak. It's so situational that in a given context, it's hard to say any particular thing is a leak.

Full Tilt Poker 100,000 Play Money No Limit Hold'em Tournament - t50/t100 Blinds - 7 players - http://www.thehandconverter.com/hands/176158
The Official DeucesCracked.com Hand History Converter

UTG+1: t2570 M = 17.13
MP: t2080 M = 13.87
CO: t1750 M = 11.67
Hero (BTN): t1505 M = 10.03
SB: t1440 M = 9.60
BB: t1365 M = 9.10
UTG: t2790 M = 18.60

Pre Flop: (t150) Hero is BTN with 2♣ 9♥
1 fold, UTG+1 calls t100, 2 folds, Hero raises to t400, 1 fold, BB calls t300, UTG+1 calls t300

Flop: (t1250) 4♣ A♣ 7♠ (3 players)
BB checks, UTG+1 bets t100, Hero calls t100, BB folds

Turn: (t1450) A♠ (2 players)
UTG+1 checks, Hero bets 1, UTG+1 folds

Hero wins t1650
----

So small bets rule.

its not a leak if the villain you are playing against is aggressive and may put you on a weak hand and decide to raise you, if you are playing against a passive calling station, then its definitely a leak and you are losing value.

Well lets say you hit top pair top with top kicker on the flop and there is a high straight draw on the board. Knowing that there are 3 or 4 others in this raised pot, do you want opponents to call your bet? You know that one out of three times, someone will hit their straight by the river so the question is should you make it unprofitable for them to call a bet by betting at least half the pot or should you take your chances that they won't hit the straight and try to build up the pot? I hope I am making sense here.

Sometimes at 10NL players seem to take small bets as weakness. Suppose you've limped with a pocket pair, flop your set (on an nonthreatening board) or a boat but are in early position with 5 behind you. In situations like this you may get 4or 5 callers with a weak bet, and maybe even a raiser after you, which is exactly what you want to build the pot.