Update: Some offers mentioned below are no longer available. View the current offers here - Starwood Preferred Guest Credit Card from American Express, Starwood Preferred Guest Business Credit Card from American ExpressLast month, American Express held form and announced an increased sign-up bonus on both the Starwood Preferred Guest Credit Card from American Express and the Starwood Preferred Guest Business Credit Card from American Express. For a limited time, you can earn 30,000 Starpoints after spending $3,000 in purchases within the first three months (or $5,000 on the business version). This sign-up bonus alone is worth $750 based on TPG’s most recent valuations. However, this offer is only around until September 14th, so you have just one more week to take advantage of it!The sign-up bonus on the SPG Amex can get you a free night at the St. Regis Deer Valley.Here’s a quick overview of the benefits on each card (many of which were just added):Personal SPG AmexLimited Time Offer: Earn 30,000 bonus Starpoints after you use your new Card to make $3,000 in purchases within the first 3 months.New: No Foreign Transaction Fees on international purchases.New: Receive free in-room, premium internet access. Booking requirements apply.New: Enjoy complimentary, unlimited Boingo Wi-Fi on up to four devices at more than 1,000,000 Boingo hotspots worldwide. Enrollment required.Earn free nights at over 1,200 hotels and resorts in nearly 100 countries with no blackout dates.Some hotels may have mandatory service and resort charges.$0 introductory annual fee for the first year, then $95Terms and limitations apply.Business SPG AmexLimited Time Offer: Earn 30,000 bonus Starpoints after you use your Card to make $5,000 in purchases within the first 3 months. Offer expires 9/14/2015.New: No Foreign Transaction Fees on international purchases.New: Receive free in-room, premium internet access. Booking requirements apply.New: Enjoy complimentary, unlimited Boingo Wi-Fi at more than 1,000,000 Boingo hotspots worldwide. Enrollment required.Earn free nights at over 1,200 hotels and resorts in nearly 100 countries with no blackout dates.Some hotels and resorts have mandatory service charges.$0 introductory annual fee for the first year, then $95.Terms and limitations applyIf you apply for the card and earn the sign-up bonus, you’ll unlock valuable redemptions like the Equinox Resort in Vermont.Other benefits on the cards include 2 stay credits and 5 night credits toward elite status each year, though if you spend $30,000 on the card in a calendar year, you’ll earn an automatic upgrade to SPG Gold. This includes some valuable benefits like bonus points, late check-out, “enhanced” rooms at check-in and a welcome amenity. It’ll also get you access to the Crossover Rewards program, which gives you additional Starpoints when you fly on qualifying paid Delta flights.The SPG Amex is a longtime favorite of TPG, and he even recommends it as a valuable option for non-category bonus spending. Starpoints regularly top his monthly valuations, and the most recent version pegs them at 2.5 cents apiece, giving you a solid 2.5% return on every purchase you make with the card. In addition to using the points for award stays at luxurious properties like the St. Regis Bal Harbour and the Prince de Galles Hotel, you can also transfer them to 34 airline partners (Korean Air was the most recent addition last month) and enjoy a 5,000 mile bonus for every 20,000 points you transfer in a single transaction.Who is eligible?Unfortunately, if you’re like me and have had the personal card in the past, you likely won’t be eligible to earn the sign-up bonus. The application page for the personal version of the card includes the following language:Sign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.“Welcome bonus offer not available to applicants who have or have had this product.“This has become standard policy with American Express cards since May 1, 2014, when the issuer stopped allowing multiple sign-up bonuses on the same card. However, if you only have the personal card and want to apply for the business version, you shouldn’t have any problem earning the sign-up bonus again, and the business card does allow you to earn multiple sign-up bonuses (as long as you haven’t had the card for at least 12 months). Just make the redemption count, since you won’t be able to take home that easy haul of points again!If you want to take advantage of the increased sign-up bonus, the clock is ticking!Bottom LineThis card represents a powerful value proposition, and the new benefits that went into effect even led TPG to pay for an international hotel stay with the card for the first time! The card also made the Top 3 on my list of best starter cards for new points and miles enthusiasts (even if you are mostly interested in free flights). However, time is running out on this increased sign-up bonus, so be sure to get your application in before September 14th.For more information on the card and the Starwood Preferred Guest program in general, check out these posts:One Year of Earning and Burning with the SPG Amex9 SPG Properties that Make for Awesome Award Redemptions9 Low-Level Starwood Properties that Make for Awesome AwardsRedeeming Starwood Preferred Guest Points for Maximum Value