Are you saying that when logged in, if you use the url ending in /77 you get the 50k offer and every other url shows you 30k? In my experience, various url endings are just a marketing tool so the company knows what ad you are responding to. Beyond that, the functionality is the same. What you're saying--that chase is requiring a specific url to identify a targeted MP account in addition to logging in--seems like overkill to me.