The Frontier Airlines World MasterCard® recently increased its sign up bonus to 40,000 bonus miles after spending $500 in the first 90 days.

The sign up bonus is extremely generous for such a small minimum spending requirement, and the miles go a long way because of Frontier's cheap award chart.

Domestic flights--including to Alaska in the middle of the summer--are only 10k miles each way.

Buried in Delta's major award chart devaluation last year was a second piece of bad news: Delta awards could no longer be put on hold under any circumstances.

But there had to be a way, I thought.

The offers for the cards listed in this post have expired, so their links have been removed. Click here for the top current credit card sign up bonuses.

Business competition is good for consumers. We've been losing airline competition rapidly for the last five years as Northwest, Continental, and US Airways have been folded into Delta, United, and American.

A new application for the US Airways MasterCard has popped up, offering 40k miles on first purchase.

Application Link: US Airways 40k Offer

40,000 Bonus Miles after your first purchase
Earn up to 10,000 Bonus Miles when you transfer a balance within 90 days of account opening (Do not do this. The 3% transfer fee is more expensive than the miles are worth!)

Earn 2 miles per $1 on US Airways purchases.

There is currently gold mine business class award availability on US Airways flights from the US to southern Europe for this summer.

Award space on US Airways flights is especially advantageous because it means that you can book the space at favorable mileage rates (and no fuel surcharges) with:

US Airways miles
American Airlines miles
United miles (until March 30, 2014)
Ultimate Rewards (until March 30, 2014)
Membership Rewards (until March 30, 2014)

What are the routes? How good is the space? How good is US Airways Business Class?

I got something wrong in today's earlier post titled American Airlines Space Bookable with US Airways Miles and US Airways Space Bookable with American Airlines Miles. I corrected the information in that post.

The Discover it® card offers 1% cash back on all purchases and 5% back on rotating categories every quarter.

You have to register for the rotating 5% cash back categories each quarter, and you can do that here.

Future 5% Categories in 2014:
October – December: Holiday Shopping (my guess: department stores and online shopping)

While most non-MileValuers love the Discover it® card for its simplicity (no annual fee, no overlimit fee, no foreign transaction fee, 0% balance transfer fee for 18 months, 0% APR for six months), there is also value in the card for people who understand rewards

Today marks a huge step forward for the integration of American Airlines and US Airways, which have already legally merged. (See integration time line here.)

Today you can use your American Airlines miles to book awards that include flights on US Airways.

You can also use your US Airways miles to book awards that include flights on American Airlines planes.

Even better: space on both airlines is now showing on both aa.com and usairways.com.

The American Airlines AAdvantage program and US Airways Dividend Miles programs are very different.

US Airways and American Airlines have merged. Citi will be the issuer of the credit card for the combined New American Airlines. Barclaycard, which currently issues the US Airways Premier World MasterCard will at some point in the very near future have to discontinue the card.

For that reason, I've recommended that people who want to get a new card get the US Airways Premier World MasterCard with 30,000 US Airways miles after first purchase before it disappears and the chance to earn the miles disappears with it.