Webjet made a net profit of $9.1 million in the six months to December 31, up from $5.6 million in the same period a year earlier.
The company's integration of Zuji helped to lift revenue by 64% to $52.2 million, while earnings rose 45% to $12.3 million.
Webjet shares were up 58 cents, or 23%, at $3.08 earlier today.
Chief executive John Guscic said investments in cloud technology, marketing and product development had resulted in a strong first half.
"We have delivered exceptional results following the transformation and integration of Zuji and major margin improvement in the core business," he said.
But he said it was too early in 2014 to make any change to the company's full year financial guidance.
Webjet has previously forecast full year earnings of $21.5 million.
The company plans to extend Zuji into Chinese language sites across Asia throughout 2014, while continuing to release exclusive deals in Australia.
Webjet will pay shareholders an interim fully-franked dividend of 6.25 cents per share, up from six cents 12 months earlier.
