Both the Malbim and Netviv distinguish between the words "biglal" and "ba'avur," both of which can be translated as "because," but which actually have different connotations. (The Malbim throughout his commentary assumes there are no synonyms in Hebrew and there must be at least subtle differences between words that seem at first glace to mean the same thing.)
"Ba'avur" implies doing something because there is some tangible benefit to be gained. Rivka tells Ya'akov to prepare a meal and bring it to Yitzchak, "ba'avur yivarechicha lifnei moso." Prepare a meal because you want to get a blessing.
"Biglal" is about logical causes, not gain/loss. G-d promised to remove the 7 nations from Canaan and give us their land "biglal ha'toeivos ha'eileh" which they did -- because of their wrongs.
Interestingly you have a pasuk in our parsha (12:13) that contains both words. Avraham tells Sarah that when they enter Egypt she should say he is her brother "l'ma'an yitav li ba'avureich" -- there is a tangible gain of wealth that Avraham will accrue, hence "ba'avur." He then adds, "v'chaysa nafshi biglaleiach" -- Sarah will be the cause of the Egyptians avoiding the crime of murder. (Shouldn't the latter point have come first? Good question, but not for this post : )
Turning back two weeks to parshas Braishis, which "because" word would you use in the sentence telling us that man was giving the earth to toil because of his sin? You would think it should be "biglal," -- sin is a logical cause. But we know that's not what the pasuk says -- it says "arura ha'adaman ba'avurecha..." (3:17) What's going on?
Malbim and Netziv explain that the pasuk is in one word giving us a beautiful lesson: man's punishment forcing him to toil is to his benefit -- it is something he can gain from and grow from. Work and toil will serve to curb his yetzer ha'ra so that the sin of eitz ha'da'as can ultimately be rectified. The punishment is itself a bracha in disguise.
Homework: check your concordance -- does the Malbim"s distinction work in all the places these words are used? I was a bit puzzled by a number of examples...