[Update 7/1/2012] The 20K spending requirement of the official 100K offer is quite high. There is an alternative easier offer - Pay $95 annual fee and get 50,000 points after 1st use and on the anniversary pay another $95 annual fee and get another 50,000 points - essentially you get 100K after paying $190 in annual fees. Compared to the official offer below, you pay an extra $95 to save $20K spending on the card - to some this is great. However, there is a little more work you have to do upfront: go to BA.com to make a booking, enter all information until the payment page, then the offer will show up, but you don't need to actually buy the ticket. Hope this helps!
[Original Post 5/14/2012] Twice in the past, Chase offered 100K for signing up a British Airways Visa. Those were the most lucrative offers ever made for British Airways credit cards. Now Chase is bringing it back again, but don't be too excited just yet if you missed the previous two offers. The spending requirement has been greatly lifted. This time, you earn 50K after the 1st purchase, an additional 25K after you spend $10K within the 1st year, and an additional 25K after you spend another $10K within the 1st year. As before, the $95 annual fee is NOT waived. So basically in order to get the whole 100K Avios (the new name of British Airways miles), you have to spend $20K within a year and pay $95. I remember the previous offers only required $2.5K spending to get 100K. For sure, it is not as great as before, but if you missed out the last two times, you may still think about it since 100K is really hard to resist!
The landing page (DEAD)
The application page (DEAD)