I've been getting targeted mail for the 50k offer for the UA Explorer card since November 2014, and finally decided it was time to grab the offer, but I wanted the $50 statement credit. As other users have described, I was able to get the offer by logging into my MP account and started the booking process. All I did was START the process (chose airports and dates), and got an ad at the top of screen for the 50k +$50 statement credit. Applied and Approved. ^