Well.... if I was to quantify it on a scale of 1 to 5, it is a 1 as far as relevance goes in the process of taking a trade. You need to be well aware of some other indicators leading up to this point of things.
I sent you a link on my last post, and here is a further clip of a day trader using DOM as an indicator as to whether he is going to take the trade. Ross Cameron at work and he has some good clips that detail trading using DOM data.
Just be clear that the video is showing a trader scalping on very small gains, and I would not recommend this to you as someone starting out. Work on a macro game at the start and work up to the micro if that is where you are headed. But it is still very handy to understand how it works all the same.