For the first time in a decade, Amazon has upped the threshold for how much you need to buy to qualify for free Super Saving Shipping.

Amazon customers have been able to qualify for free shipping on their purchases via the Super Saver Shipping program by purchasing $25 in qualifying merchandise for the past decade. That threshold has now been raised to a minimum of $35.

Increasing shipping costs are sure to have played a part in the decision, but the page where Amazon explains the increase also spends a good amount of time discussing the benefits of joining the company’s subscription shipping service, Amazon Prime.

Millions of Amazon customers have already made the choice of faster shipping by becoming Amazon Prime members. Prime includes unlimited Free Two-Day Shipping, with no minimum order size, on more than 15 million items, as well as unlimited streaming of over 41,000 movies and TV episodes through Prime Instant Video and access to over 350,000 books to borrow through the Kindle Owners’ Lending Library. The service is so popular that more than a year ago we began shipping more items with Prime than with free shipping. Click here to start a 30-day free trial of Amazon Prime.

This seems like a fairly obvious play to get more customers interested in the program, and it makes sense. Amazon has been turning Amazon Prime into a huge leader for the company to lure more customers that much deeper in the ecosystem. If even a small percentage of the customers who relied on Super Saver Shipping make the transition, it could be a major boon to the service.

The changes to Super Saver Shipping take effect immediately.