I figured that opening the standard link to the business gold card (
https://www.americanexpress.com/us/s...s-gold-rewards) on a mobile device can result in a 50k or 75k offer appearing.
If you click from a computer, it shows 25k. But if you COPY the link and paste in a browser on your phone or iPad you can get the higher offer. I copied the link into a new Chrome browser on my iPhone and got a 75k offer but if I copied into Safari, I only got a 50k offer. Incognito mode did not make a difference for me someone else replied to me on Twitter and told me it helped them get the 75k offer. Additionally, I was NOT logged into my Amex account.
No idea why this works like this but it does and several have confirmed the 75k bonus with Amex once approved. I posted more details and screenshots about it on my blog.
http://pointscentric.com/2014/11/10/...-50000-points/