To make betting possible, the point spread is needed. This is the book makers way of evening out the betting between the teams in effort to have the same amount on either side of the bet while they sit back and collect their ten percent at no risk.
NFL Spread Betting
But as with any betting, the spread is only one consideration. More important for you to think about is the motivating factors of the teams and their situation. A team that is playing at home or having a good player return from injury can be highly motivated, for example.
In reality, NFL spread betting is the bookies attempt to make it coin toss odds, and it works well to even the teams out. But it can also be exploited to your advantage with the right kind of betting system.
Just remember, the sports books all adjust for every system that is published, for free or for sale. The best systems are kept secret by the professionals because their odds would suffer if it got out.
But you can build your own NFL system and do the same thing (keep it secret). That is still the best way to exploit NFL spread betting.