It has been about a month since ABC showed the season finale of “Shark Tank,” the reality show that gives entrepreneurs in search of financing a chance to plead their cases before five tough-talking investors, or “sharks.” At VerbalizeIt, a technology start-up that was part of this season’s final segment, the effects of the show’s appearance can already be quantified.

The start-up’s co-founders, Ryan Frankel, 29, and Kunal Sarda, 31, promote their company as the world’s only instant, 24-7 “human-powered” translation service. Inspired by a harrowing episode when Mr. Frankel could not communicate the symptoms of a virulent stomach bug to a pharmacist in Beijing, the service takes just 15 seconds to put mobile users in touch with a human translator fluent in both English and any of 11 other languages. In other words, it combines the speed of Google Translate with the precision of a traditional translation service — at least that was the pitch Mr. Frankel and Mr. Sarda made to the sharks.

Within 72 hours of the segment being shown, 20,000 new customers had downloaded the VerbalizeIt app, according to Mr. Frankel. Daily revenue, he said, more than tripled. The company charges about $1.50 a minute from individual consumers and as much as 27 cents a word from businesses that use the same network of about 10,000 freelance translators to translate documents and videos.

The segment became one of the most debated of the show’s fourth season. Many “Shark Tank” followers discussed on chat rooms, blogs and Twitter how Mr. Frankel and Mr. Sarda erred when they turned down an offer of $250,000 for 25 percent of their company from Mark Cuban, a shark who owns the Dallas Mavericks and has previously invested in translation companies.