To fold or not to fold

[B-squared]

Full Tilt No-Limit Hold'em, $0.02 BB (5 handed) - Full Tilt Converter Tool from http://poker-tools.flopturnriver.com/Hand-Converter.php

Literally first hand, just sat down, no reads.

UTG ($3.20)
MP ($0.89)
Button ($1.36)
SB ($0.57)
Hero (BB) ($2)

Preflop: Hero is BB with 3, 4
UTG calls $0.02, MP calls $0.02, 1 fold, SB calls $0.01, Hero checks

Flop: ($0.08) 6, 7, 8 (4 players)
SB checks, Hero checks, UTG checks, MP checks

Turn: ($0.08) 5 (4 players)
SB bets $0.08, Hero calls $0.08, UTG calls $0.08, 1 fold

River: ($0.32) J (3 players)
SB bets $0.24, Hero?????

I folded, UTG called and SB won with a 8-high straight. I'm unsure how to analyse if my fold was correct or not, particularly that I didnt have any of my opponents on a range. What do you think?


HAND #2:

Full Tilt No-Limit Hold'em, $0.02 BB (6 handed) - Full Tilt Converter Tool from http://www.flopturnriver.com

BB ($0.98)
UTG ($2.25)
MP ($1.98)
CO ($0.19)
Button ($1.15)
Hero (SB) ($2.17)

Preflop: Hero is SB with J, 4
UTG calls $0.02, MP calls $0.02, 1 fold, Button calls $0.02, Hero calls $0.01? BB checks

Given that i'm investing 1c into a 9c pot: 1/(1+9) = 10, I only need to win 1 in 10 times to make the call profitable, right? Doesn't this (given a table with an arbitrary mix of both looser and tighter kinds of players) make a call in this position with almost anything (short of say, 72o) profitable?