A new business in Philadelphia wants to make it much easier to "buy American" online. 

American Certified is the brainchild of Marvin Weinberger, and the e-commerce service basically boils down to this: Take a massive digital haystack and devise a technology to find all the American-made needles.

"We've spent the last 18 months figuring out ... how to automatically filter from Amazon's inventory of 224 million products those products which meet our standard for American-made," Weinberger said.

The company has found about 1.7 million of those products, so far. Weinberger says he hopes to bring in another 8 million products in the next month or so.

American Certified makes a commission (up to 8.5 percent) from Amazon on every sale. The hope is to tap what people self-report as a widespread demand for American-made products.

Weinberger thinks people will put their money where their mouths are, and that American Certified's technology will make it easy for them to do so.

"American Certified is a one-stop shop for American products," Weinberger said. "It's the largest selection in the world."

The shop launched May 15. Weinberger says his team had to start from scratch six times to get the product-filtering technology just right.