25nl: River bet or check behind?

[RMLewis]

Villain is 49% vpip over 75 hands
should i have saved my 6.75 or was it ok to bet?

Absolute Poker
No Limit Holdem Ring game
Blinds: $0.10/$0.25
6 players
Converter (http://www.neildewhurst.com/hand-converter)

Stack sizes:
UTG: $15.25
UTG+1: $11.55
CO: $12.75
NYYRico38: $22.20
SB: $29.57
BB: $57.85

Pre-flop: (6 players) NYYRico38 is Button with T/images/graemlins/club.gif A/images/graemlins/club.gif
2 folds, CO calls, <font color="#cc0000">NYYRico38 raises to $1</font>, 2 folds, CO calls.

Flop: 9/images/graemlins/heart.gif 2/images/graemlins/diamond.gif 2/images/graemlins/spade.gif ($2.35, 2 players)
<font color="#cc0000">CO bets $1</font>, NYYRico38 calls.

Turn: A/images/graemlins/heart.gif ($4.35, 2 players)
<font color="#cc0000">CO bets $1</font>, <font color="#cc0000">NYYRico38 raises to $4</font>, CO calls.

River: 6/images/graemlins/spade.gif ($12.35, 2 players)
CO checks, <font color="#cc0000">NYYRico38 bets $6.75</font>, <font color="#cc0000">CO calls all-in $6.75</font>.

Results:
Final pot: $25.85

[halinc]

Villain played the flop and turn like a huge number of NL25 players play a 9 there on a paired board, or like 6's. So without any other exceptional read, I think you'll get called enough by like a mid-pair (especially by a short-stack-- how'd he get short?) to make it profitable.