Los Angeles, Nov 18 (DPA) Sarah Palin's widely touted memoir, 'Going Rogue', went on sale Tuesday as the former Republican vice-presidential candidate gave her clearest hint yet that she may take part in the 2012 presidential race.

'My ambition is to help our country in whatever role that will be,' she said in an interview with US news doyen Barbara Walters. 'I cannot predict what doors will be open in 2012.'

Asked if she would play a major role in that campaign, she replied: 'If people will have me, I will.'

The US media has given the book launch a huge amount of coverage. The Wall Street Journal reported that demand for the 413-page book is so high that HarperCollins Publishers is going back to press for an additional 100,000 run, bringing the total number of hard-covers in print to 1.6 million copies.

Palin, who was a surprise pick of John McCain for his running mate, was often derided during the 2008 campaign as being uninformed on major issues and unqualified for the presidency. Yet she maintains a strong core following, especially among social conservatives.

The launch of the book, which is already a bestseller based on advanced orders alone, had reignited many of the old debates about the Palin phenomenon, as well as the obsessive media interest in the former governor of Alaska.

But not all those buying the memoir count themselves as fans. 'I would never vote for her, but I find her strangely fascinating,' said one buyer at a book store in liberal San Francisco. 'I want to understand what makes her tick, and why so many people would vote for her despite her obvious flaws.'