There are two credit cards with large sign-up bonuses that are set to expire this week.

The CitiBusiness/AAdvantage Platinum Select World MasterCard: 70,000 bonus American Airlines miles for spending $4,000 on the new card within three months of account opening. You must apply by today (October 9, 2018) to qualify for this bonus offer. 
The Citi ThankYou Premier: 60,000 bonus ThankYou Points for spending $4,000 on the new card within three months of account opening.

There are just two days left to take advantage of the 30% transfer bonus between Citi ThankYou Points and Flying Blue, and three days left to book Flying Blue's August Promo Awards...the cheapest of which will get you from New York City to Paris for only 8,000 ThankYou Points if you stack both promotions.

The Citi ThankYou Premier Card is now offering 60,000 bonus ThankYou Points after $4,000 in purchases within the first 3 months of account opening. For the majority of 2016 the ThankYou Premier had no sign up bonus whatsoever, then Citi came back with 40k points for a $3k minimum spending requirement bonus in December 2016. Since then we’ve seen the bonus fluctuate between non-existent to typically no higher than 50k. 60,000 ThankYou Points is the biggest bonus the card has ever offered.

The Citi ThankYou Premier Card currently has an offer of 50,000 bonus ThankYou Points after $4,000 in purchases within the first three months of account opening.

According to One Mile at a Time, that sign up bonus is changing tomorrow, August 22. This is not shocking considering that, for the majority of 2016, the ThankYou Premier had no sign up bonus whatsoever. Then in December of 2016, Citi came back with 40k points for a $3k minimum spending requirement bonus.

The Citi ThankYou® Premier Card comes with 40,000 bonus ThankYou Points after $3,000 in purchases within the first 3 months of account opening. Those 40,000 points are now worth $500 toward airfare, hotels, cruises, and car rentals (25% more.)

I went into my thankyou.com account to search for car rentals, and the results showed a 1.25 cents per point valuation.

It's fantastic that Citi made car, hotel, and and cruise redemptions more valuable, but I don't expect to use this new benefit.

The Citi ThankYou® Premier Card changed its 3x categories to gas and travel on April 19. I covered just how broad those categories are in this post at the time.

Gas and travel purchases that earn 3 ThankYou Points per dollar include:

airlines
hotels
car rental agencies
travel agencies
gas stations
commuter transportation
taxi/limousines
passenger railways
cruise lines
bridge and road tolls
parking lots/garages
campgrounds and trailer parks
time shares
bus lines
motor home/RV Rental and boat rentals

At the time of the change, I hoped that Uber fell into the taxi/limousines category.

The Citi ThankYou® Premier Card now offers 40,000 bonus ThankYou Points after $3,000 in purchases within the first 3 months of account opening.

Not to be confused with the Citi Prestige® Card, which has the same sign up bonus but totally different benefits.
Quick Facts

Sign Up Bonus: 40,000 ThankYou Points after $3,000 in spending in the first three months
Category Bonuses: 3x on travel and gas, 2x on restaurants and entertainment
Value of ThankYou Points: Worth 1.25 cents toward the purchase of any cash ticket (or up to 1.6 cents if you also have a

The Citi ThankYou® Premier Card now offers 40,000 bonus ThankYou Points after $3,000 in purchases within the first 3 months of account opening.

Not to be confused with the Citi Prestige® Card, which has the same sign up bonus but totally different benefits.
Quick Facts

Sign Up Bonus: 40,000 ThankYou Points after $3,000 in spending in the first three months
Category Bonuses: 3x on travel and gas, 2x on restaurants and entertainment
Value of ThankYou Points: Worth 1.25 cents toward the purchase of any cash ticket (or up to 1.6 cents if you also have a

The Citi ThankYou® Premier Card changed its category bonuses today and lowered its annual fee.

The Citi ThankYou® Premier Card changed its category bonuses today and lowered its annual fee.