The answer lies somewhere in-between quality and quantity. With a hyper competitive industry like online gambling, the reality is that you do have to have a substantial number of links, but if you can get 1 high quality link, it could have more power than 100 garbage links (this is just a generic example).
The problem is that the search engines don’t give you the exact detail of what you should be doing, so plenty of sites are going all out to gain as many backlinks as possible, while others are only looking at strategic link placements (ie: high quality). Not to say that either strategy is right or wrong, but the point is that somewhere in the middle is where the importance lies for the search engines. If anyone ever figures out the true formula, they will be rich.