Mastercard BOGO beats Visa's 3-for-2 for short ITC stays.

The 40% conversion bonus between Singapore Airlines KrisFlyer and Shangri-La Circle points sounds generous, but the base ratios are terrible. Converting KrisFlyer miles to Shangri-La points yields 12 miles for 1.3 points - that's under 0.11 points per mile. Going the other way, 1 Shangri-La point becomes 1.625 KrisFlyer miles, a rate that values a hotel point at less than 2 miles. With a 180,000-mile annual cap and a minimum of 20,000 miles per conversion, this is only for members who already have a specific use for Shangri-La points. The top 10 converters get an extra 10%, but that's a lottery, not a strategy.

Miles&Smiles members can earn triple miles on up to three Wyndham stays booked by November 4 and completed by December 31, but only if they flip their earning preference to Turkish Airlines. Blue and Gold members get 3 miles per USD at most Wyndham brands; Platinum and Diamond get 6 miles per USD. The general advice is to collect Wyndham Rewards points under their usual global promotion and convert them to airline miles if you choose. So this triple-miles switch only pays if you specifically need Miles&Smiles miles.