Parkdean Resorts said moves to upgrade its sites with better restaurants and indoor facilities had also helped bookings to step up 11% in 2016.
It said the boost was partly driven by people ditching a lengthy summer holiday in favour of taking shorter breaks more often, stretching the holiday season into the Spring.
But the wider industry trend suggests travellers are also opting for "safer" holiday destinations at home or in the Mediterranean following a spate of terror attacks overseas.
Parkdean Resorts was created last September following a £960m merger between Parkdean and Park Resorts, creating a business with 72 holiday parks and 35,600 pitches.
Chief executive John Waterworth said the firm invested £36m in 2015 and would drive £40m into the business this year.
"Capital investment in new facilities, refurbishment and park enhancement and expansion is reaping reward, as is investment in our people and extending the holiday season.
"In 2015 we sold almost half a million holidays, demonstrating that our marketplace is growing. The scale of the merger has brought national sales capability for the first time and merger synergies will flow through in the current year and beyond. 2016 has begun strongly."
He said the company was keen to keep expanding through acquisition, but had no deals in the pipeline.
He added: "There are about 4,000 holiday parks in the UK, and some of these are quite small, but we would be looking for parks with more than 150 pitches."
The company, which is part owned by Alchemy Partners and Electra Private Equity , said its combined pro-forma revenues for last year reached £400.7 million, up 8% from £370.7m in 2014.
Underlying earnings also rose to £106.6m in 2015, up 15.7% from £92.1m the year before.
It said holiday sales, caravan and lodge sales, spending on its sites and owner income all recorded growth last year.
Holiday hire revenues also climbed 11.5% in 2015. The group sold 492,000 holidays and had two million customers.
The firm's current investment drive will help bolster its retail facilities, add 240 holiday home pitches and bring 400 replacement and upgraded caravans and lodges to its sites.
It said it will also look to capitalise on the extended holiday season by buying more double glazed centrally heated caravans and lodges.