It will be a huge reward for many of its loyal shareholders who have ignored the company's critics and religiously followed the dream of being the third force in iron ore. They lapped it up on Monday, pushing the share price up 6.5 per cent.

Fortescue's previously parsimonious strategy on paying dividends came to an end as it declared on Monday that up to 80 per cent of profits will be earmarked for paying shareholders going forward.

Forrest himself could be counting on a yearly pay cheque of more than half a billion US dollars from 2018 if current profit levels are maintained and more if profits improve.

Fortescue's generosity to shareholders marks the final stage in its evolution from a highly speculative, entrepreneurial upstart to a mature company with reliable positive cash flow - albeit volatile thanks to movements in the iron ore price.

Until now, the company had been squirrelling profits to pay down the billions in debt it had taken on to develop the West Australian mines and infrastructure.

The other leg of its strategy had been to cut its operational costs - at which it has been so successful that it is ahead of its larger rivals in iron ore - Rio Tinto and BHP.

The release of Fortescue's full-year results on Monday coincided with yet another strong gain in the price of iron ore - which if sustained - would improve profits in 2018.

It told investors that net direct (C1) cash costs should fall again in 2018 to between $US11-12 per wet metric tonne and that the company would continue to work to get below even these levels.

But there is always the caveat that this will depend on fluctuations in the Australian dollar exchange rate (which is now stubbornly higher than Fortescue's assumptions of US75??) and fuel prices of $US53 a barrel.

The 2017 result of a $US2.1 billion net profit was more than double that which was inked in 2016, primarily due to the better iron ore prices from its Chinese customers.

The result would have been better but for the price discount Fortescue wears because its iron ore grades are lower than its major competitors'.

And with debt now down to near optimal levels and no major repayments due until 2022, the familiar mantra of Fortescue pumping its cash into debt repayments has given way to a new emphasis on shareholder returns.

In 2017 alone, net debt was cut in half, to $US2.63 billion from $US5.19 billion a year earlier.

Indeed, it now boasts a very healthy looking balance sheet, having avoided (unlike BHP and Rio) the pitfalls of blowing up capital on poor acquisitions.

There was no talk of any large capital outlays from Fortescue nor of increasing the production of ore beyond its current 170 million tonnes a year, although it will need to replace some reserves over the coming years.

Fortescue is almost starting to look like a yield stock.

It's a formidable achievement for a company that only a few years back was battered by lower ore prices and too much debt, and being read last rites by some commentators.

If one assumed a steady-state for Fortescue, investors should be feeling pretty comfortable with the reduced risk level complete with net gearing of around 21 per cent.

But this is a company that is probably unable to shed its entrepreneurial culture, which is dominated by Forrest. He will not be content with sitting back and enjoying the fruits of the past 15 years of hard slug and just harvesting dividends.

Analysts are now bracing themselves for Fortescue 2.0 - a company which, armed with enormous cash flow, is looking for new opportunities, new commodities and new ways to get bigger.

The company's chief executive, Nev Power, has to balance the branding of the company as one with growth options beyond West Australian iron ore but at the same time not willing to take on too much risk.

At this stage, Fortescue has barely dipped its toe into potential new developments and Power insists it won't grow for growth's sake. Time will tell.