In learning the key factor is motivation. To quote Plutarch the philosopher, education is cultivating the flame, not filling a vessel. If someone is truly motivated she will learn fast.
The idea in Verba is to make foreign vocabulary learning more motivating. You watch YouTube about the subjects you are interested in, and Verba shows subtitles captured from speech, highlighting new words, i.e. words not found in your word chest . If you have a Verba account, you accumulate words familiar to you into your personal word chest, and not get bothered about them any more. Only the new intriguing words are highlighted for you to memorize, should you wish to. Old fashioned underlining textbooks, brought to digital age.