Since US Airways joined the oneworld Alliance on March 31, I think they have the most valuable miles of any airline. The three main reasons:

The world's cheapest award chart.

The Frontier Airlines World MasterCard® currently offers one of the best sign up bonuses for a tiny minimum spending requirement: you earn 40,000 bonus miles after spending $500 in the first 90 days.

Now the card is offering 0% Intro APR on purchases and balance transfers for the first 12 months.

United is offering 25% off Saver economy awards between the mainland United States and Japan for flights completed by April 30, 2014.

You can book flights to Japan for only 26,250 United miles each way this month only, and the price shows up automatically online. The normal price is 35,000 United miles each way.

Any discount is nice, but there are one or two drawbacks to consider.

On Monday, I wrote about US Airways and TAM joining the oneworld alliance. That meant that US Airways and TAM flights were now bookable with British Airways Avios, a founding member of oneworld.

In the renewed interest in searching ba.com for award flights, there were some hiccups that people noted in the comments. Often the best way to plan an Avios award is to search aa.com, and then when you find the award space you want, go to ba.com to book it.

AA.com and ba.com didn't seem to be matching up in the availability that you could book.

There are several posts on the new PointBreaks list, which allows us to book hotel rooms through May 31, 2014 for as low as $28.75 per night. Even if you’ve read those, read this. I’ve honed my strategy for getting $35 or less per night rooms quite a bit, and I want to share it, so everyone can have access to the best practices.

IHG Rewards Club, the loyalty program of Holiday Inn, Crowne Plaza, InterContinental, and more is selling points with targeted 25% to 100% bonuses.

Check your email for the subject line "Reveal your mystery bonus" or click this link.

After typing in my account information, I was offered a 100% bonus on points purchases through April 21, 2014.

At what levels of this promotion would I consider it a good deal to buy IHG points?

The normal prices of IHG points range from 1.15 to 1.35 cents each depending on how many you buy.

With my 100% bonus, I can get

Frontier has announced a 14% discount on domestic flights bought by Thursday April 3, 2014 and flown by June 12, 2014 with promo code NOFOOLIN. Sale fares apply every day except Fridays and Sundays.

This 14% discount does not apply to Frontier’s international destinations like Jamaica, Mexico, Costa Rica, and the Dominican Republic.

To get to those places, your best bet is to redeem 15k Frontier miles each way.

I'm interested in the businesses behind loyalty programs, so I always wonder:

What did that credit card company pay that airline for its miles?
How much does American Airlines pay Qantas when an AAdvantage award includes a Qantas leg?
How much did that hotel loyalty program reimburse that specific hotel for the free stay I just took?

Well last month I stayed at the Radisson Martinique of Broadway (review here), and I know exactly how much Club Carlson rei

US Airways joined oneworld today, March 31, 2014.

TAM, the largest airline in Brazil, joined oneworld today March 31, 2014.

You can now book a one way flight from the United States to Brazil for 4,000 Avios and $97.50!

TAM flights are bookable with American Airlines miles and British Airways Avios and searchable on ba.com. American Airlines and British Airways do not collect fuel surcharges on TAM flights.

TAM has flights between Brazil and New York-JFK, Miami, and Orlando. All three American cities have flights to Rio de Janeiro–Galeão and São Paulo–Guarulhos.