Damn good question. I pondered over this one for a while. Two...

Damn good question. I pondered over this one for a while. Two thoughts:
1. the original contract was signed a few years ago (?) and the margins reflected the boom times and/or
2. QUB in today's reality is OK with shaving the margin to get new business and with the resultant publicity of the new contract (indeed you've noticed it and companies needing haulage will notice it too) will invite more enquiries which could result in further new contract business with margins edging higher.
Only theories of course. Also, keep in mind the pricing terms which QUB put into place with Atlas. Reduced margins to assist a financially troubled customer but the terms change if/when those problems are resolved. I am suggesting that QUB has shown the ability to flexible and creative in pricing to attract new business. Cheers!