Rightmove increased its profit margin to 75.1% last year, up from 74.5% in 2014, it announced this morning.

Revenue was up 15% at £192.1m, with underlying profit up 16% to £144.3m.

Rightmove’s agency business was easily the main contributor to overall revenue with a year on year increase of £17.5m to £147.1m.

Rightmove’s market share among the top four property portals was 77%, up from 74% at the start of last year.

Rightmove also raised its dividend to shareholders by 23% to 27p from 22p.

Average revenue per advertiser – mostly estate agents – was up at £754 per month compared with £684 the year before.

The number of advertisers on Rightmove was also up, by 2%, to stand at a record 19,752. The number of agents on Rightmove rose 3%.

The site had almost 50% more properties listed on it than any other portal, with 1.2m properties displayed on December 31, 2015.

Visits and leads were also up, with a record 1.3bn visits last year (a rise of 18%), with a record 49.8m leads generated for advertisers, compared with 42.8m the year before – a rise of 16%.

CEO Nick McKittrick said: “Rightmove celebrated its 15th birthday in 2015 and together with the support of nearly 20,000 customers, it has changed the way Britain searches and researches property.

“Our property stock advantage coupled with our brand strength and innovation have substantially increased our audience size and engagement this year.

“We attracted 200m more visits in 2015 as more people came to search and research the only place with a million properties for sale and to rent in the UK.

“We help our customers succeed by delivering great value marketing and by helping drive business efficiencies. We have grown our customer base by 2% during 2015 to a record high and continue to build broader relationships to support customers’ ambitions.

“We continue to break records at the start of 2016 having already generated over 9m leads for our customers.”

Chairman Scott Forbes said: “As we report on our 15th consecutive year of growth, I’d like to pick up on a theme raised in the Strategic Report: ‘Doing the right thing’.

“This uncompromising principle supports the ethos of the Group. The philosophy drives our high achieving network business and what we do for our trade customers on one side of the network and our web and mobile visiting consumers on the other side.

“It also extends to our focus and behaviours towards all stakeholders including our investors, analysts, employees and our Board.

“The team’s relentless focus and sensitive examination of our consumer experience has been the catalyst for continual improvements to site navigation and design.

“We aim for simplicity of use and an engaging experience.

“Of course our site traffic is in part a natural consequence of the best consumer proposition in the market, with almost 50% more listings than any other UK property portal, but it is in the main driven by the huge trust built up in our brand over the past 15 years.

“The team works diligently to maintain a site that delivers the desired information when it is wanted and in the form it is wanted and we achieved an enviable 99.997% level of site availability last year.

“Our nearly 20,000 customers have benefited from our ever-growing popularity with the British home moving public. We have delivered 15 consecutive years of site traffic growth for our customers and have been consistently ranked in the top ten sites in the UK irrespective of cyclical housing demand.

“Last year we attracted 200m more consumer visits than the previous year and generated a record 50 million leads for our customers. Rightmove’s popularity is showing no signs of letting up and we have already set new site traffic records this January.”

He went on: “Our customers have also benefitted from a continuous roll-out of additional advertising products to reach their audience of home sellers, landlords and home hunters.

“There is a wide range of choice and discretion to shape and reinforce brand identity on Rightmove to compete for business and market homes.

“There is also an increasing range of valuable tools, support and data available to our customers to assist them to operate their businesses more effectively and efficiently.”

Praising the talent and dedication of Rightmove staff, Forbes said Rightmove had become “the essential marketplace for home hunters to find their next home and for property advertisers to reach by far the widest possible audience”.

Ahead of today’s results, with their astonishing new records, shares in Rightmove rose £1.39 yesterday.