In 2006, the two began exploring the possibility of applying similar computerized methods to visual searches. They called their new start-up Link-It. Much in the same way that Google is a search engine for text, Siri for voice, and music discovery apps like Shazam help people match songs they hear on the radio to an artist and song title, Superfish aimed to be a “visual search” engine for images.

With 12 Ph.D.s on staff and 10 patents for visual search technology, the company’s software crawls the web, using mathematical models to catalog, analyze and match images of plants, dogs or furniture to the exact flower, dog breed or home goods retailer. At one point, they worked with Samsung on a proof-of-concept visual search engine on Samsung cellphones, but a formal partnership was never consummated.

In 2009, the co-founders said, they renamed the company Superfish.

Five years later, Superfish had accumulated partnerships with more than 100,000 retailers that paid the company through “affiliate” programs, in which retailers gave Superfish a cut of each sale its software encouraged. As Superfish tracks products that appeal to people on the web, its technology serves ads of similar or identical products from its retail partners.

Last year, Superfish began experimenting with new sources of revenue. It released a series of free “LikeThat” mobile apps at the iTunes and Android store, such as LikeThat Décor, an app that allows design aficionados or interior designers to snap shots of furniture so that Superfish can locate the same, or similar, products online.

The start-up’s executives say they approached Lenovo, based in China, early last year about the possibility of loading their VisualDiscovery software onto its PCs at the factory.

The pitch, Lenovo’s executives recall, was that Superfish could “improve our consumer experience” by serving its customers more relevant ads.

“The motivation was to enhance the experience,” Peter Hortensius, Lenovo’s chief technology officer said in an interview last week. If a consumer was hovering his mouse over a vase, Mr. Hortensius said, Superfish technology would register his interest in the vase and could show a similar vase, or the same vase at a cheaper price, from a different retailer.