Alastair Weng shares the secrets to his academic success for less than the price of a coffee.

The University of Melbourne science student is among thousands of young Australians who are converting their lecture and textbook notes into cash.

Alastair Weng is one of many students selling their lecture notes online. Credit:Paul Jeffers

Hundreds of students have paid $3 to access Mr Weng's neatly formatted biology and chemistry notes, which he uploads on a website called NoteXchange.

"It's a little bit of pocket money on the side," the 19-year-old said.