Comparing the odds gives you another interesting option - a sure bet called also an arbitrage bet. If you know exactly what this definition means and you need no additional information about sure bets you will probably would like to look at free sure bets list.
And briefly: playing sure bets is probably the only way to get a real chance to win against bookmakers.

View an example of Sure Bets!

Sure Bets Finder:   All - Today - Tomorrow - Next 3 Hours - Next 12 Hours - Top

FBUSL PDL 13
2013-06-18 00:00:00	1	x	2	Pr %
Kansas City Brass-Springfield Demize	11	1.45	8	10.43

Soccer | Asia | World Cup Qualifiers - Asia
2013-06-18 13:00:00	> 1,5	< 1,5	Prof. %
Korea Republic - Iran	1.8	2.68	7.67857

FBPER Primera Division 13
2013-06-19 00:00:00	1	x	2	Pr %
San Martin-Cesar Vallejo	3.1	3.2	3.2	5.53

Lithuania Lithuanian A lyga
2013-06-18 17:30:00	1	2	Prof. %
Atlantas - Banga Gargzdai	2.42	1.86	5.17

Soccer | North America | MLS
2013-06-20 03:00:00	> 2,5	< 2,5	Prof. %
Vancouver Whitecaps - Chivas USA	1.95	2.25	4.46429

Tennis | World | ATP - Eastbourne (GBR) - Grass
2013-06-18 12:30:00	1	2	Prof. %
Jarkko Nieminen - Feliciano Lopez	2.75	1.67	3.90271

World ATP Challenger Tanger
2013-06-18 11:20:00	1	2	Prof. %
Kukushkin Mikhail - Giner Marc	1.28	5.50	3.83

Soccer | Peru | Descentralizado
2013-06-20 02:00:00	> 2,5	< 2,5	Prof. %
Alianza Lima - Sporting Cristal	2	2.15	3.61446

Peru Peruvian Primera Division
2013-06-20 01:00:00	Over	Under	Prof. %
Alianza Lima - Sporting Cristal	2.00	2.15	3.61

World ITF Montpellier Women
2013-06-18 08:00:00	1	2	Prof. %
Ferrer Suarez Ines - Hesse Amandine	1.72	2.59	3.36

The technique also known as sports arbitrage or Sure Bets is a great way to earn without losing sports betting, it all depends on your budget.

Logically, on a limited budget of 100 euros and a SureBets with 3% profit, the gain is relatively low, so you should be able to invest a greater sum of money to see increased investment faster.

We also have a list of the best bookmakers, that having more shares than others, where there are often Sure Bets.

So, having said that, needless to say good luck, since it is no longer to win a bet, but you will start to talk about a real job.