Karma is a horrible idea.
Events occur, and because of this idea, one resorts to past experiences which may have caused it.
It's a way to re-hash memories of failed accomplisments or mis-deeds.
Not benifical in any way.
I've had my cards read a few times in the past week, and by no means is this a flawless way of predicting ones future, but it seems more benifical then karma ever could be.
It dives into the subconcious, and brings out thoughts or ideas, desires, or wants that have not previously been thought upon.
Your interpretation of the cards laid before you, are not finite. There is no firm reason on why things are or how they will be.
It aids you in looking outside the box.
It is not witchcraft.
It is not a sin.
It's getting you to look at a situation with a different set of eyes on how things truely are or could truely be.
Maybe this is why they get a bad rep.
They make you think.