I will warn that the published Terms & Conditions (which I don't think you can see prior to joining) may make the deal less desirable:
- Discount applies to members of FoundersCard.
- Discounts are based on round-trip purchase of any published retail World Traveller (economy), World Traveller Plus (premium economy), Club World (business), or First Class fares on ba.com via the exclusive link on flights marketed by British Airways from North America and United Kingdom. The discount is applied to base fare only and is not applicable to any fees, taxes and surcharges.
- Discounts are valid for outbound travel through – October 30, 2016.
- Fares will include taxes, fees and carrier charges of approximately $695 to $1268, correct as of February 20, 2014 and a $2.50 September 11th Security Fee.
- For new bookings only made by October 30, 2016.
- Valid on British Airways coded flights only. Operating carrier may include British Airways, American Airlines and Iberia.
- All rules of any fare purchased apply, including advance purchase, minimum/maximum stay, stopovers, weekend add-ons, change fees and cancellation/refund rules. Please refer to individual rules per ticket before purchase.
- Executive Club members can earn Avios per the terms and conditions of the Executive Club.
- Discounts can only be booked online through this offer. The exclusive discounts will not apply if booked through a British Airways call centre or travel agent.
- Infant without seat will pay 10% of adult fare. Child discount will allow for a child to pay 75% of the adult fare.
- Unaccompanied minors permitted for a $75 surcharge each way.
- Open to NA residents paying in US/CA dollars only, with travel originating in North America.
- Subject to availability.
- Cannot be combined with any other offer.
- This offer may be withdrawn or limited by British Airways without notice.
- Other significant restrictions may apply.
Most notably the fact that the deal apparently expires in a bit over a week, and according to the T&C's travel needs to be completed by then. I will say that FC does renew their deals much of the time (though not always) and I did a mock booking NYC-PRG and saw the 10% discount for mid-November dates. But I also tried an intra-Europe flight (LGW-IBZ) for June and didn't see the discount. But that might also be the other problematic T&C's: It's for North American residents and requires travel to originate in NA.
Although I'm not actually sure that's a real requirement, since when I repeated my mock mid-November trip to Prague but this time departing London I see the discount, so the mock Ibiza booking might just be past the end of the deal pre-renewal.
In any case I wouldn't recommend anyone get a FC membership for the BA benefits until the renewal of the BA deal is certain (I've set a reminder for myself to check on Nov 2), unless the other deals that FC offers are useful. I primarily belong to get the Diamond status from Caesars Entertainment casinos' Total Rewards program but use a number of the other options occasionally.