Third-party sellers on the Amazon Marketplace generated sales of more than $3.5 billion during the company’s recent Prime Day promotions on behalf of small and medium-sized businesses. This represents an increase of nearly 60 percent from last year’s promotion, outstripping the growth in Amazon’s own sales.

Prime Day took place first in India in August and then ran in 19 other countries on Oct. 13-14. It was exclusive to members of Amazon’s Prime subscription service, which waives shipping fees on all purchases and includes other services. The associated discounts amounted to more than $1.4 billion. Besides the U.S., the new markets included the U.K., Spain, the Nedtherlands, Italy, Germany, France, Belgium and Austria.

Home, Electronics and Nutrition & Wellness were among the major categories. Aside from numerous other items in all these segments, one of the most sought-after products in the U.S. and Canada was the LifeStraw Personal Water Filter, which sold out on the first day – and thereby triggered the company’s Give Back program for about 200,000 children. According to LifeStraw, each child will be getting access to a school year’s supply of clean drinking water. The Fitbit Versa 2 Health and Fitness Smartwatch also sold well.

Most of Amazon’s third-party sellers are small and medium-size enterprises (SMEs), and Prime Day was, according to the company, tailored to them. This year it expects to spend some $18 billion to streamline their operations on the platform.

Moreover, by the company’s reckoning, Amazon’s two-week promotion in the run up to Prime Day – its largest ever – helped drive some $900 million in sales to the SMEs. This included the Spend $10, Get $10 program, which earned customers “tens of millions of dollars in credits.” These are redeemable with Whole Foods Market, Amazon Fresh, Amazon Go, Amazon Go Grocery, Amazon Books, Amazon Pop Up, and Amazon 4-star stores.

In September, Amazon announced a staff expansion of 100,000 full- and part-time employees for its fulfillment and logistics network throughout the U.S. and Canada.