BOSTON (Reuters) - Billionaire investor William Ackman took his fight for board seats at Automatic Data Processing Inc to retail investors on Tuesday in an unusually public format where he detailed his successes and failures and urged all to cast their votes.

FILE PHOTO: William Ackman, founder and CEO of hedge fund Pershing Square Capital Management, speaks during the Sohn Investment Conference in New York May 4, 2015. REUTERS/Brendan McDermid

For one hour, the Wall Street hedge fund manager spoke in a live webinar, fielding questions from Main Street investors about ADP’s culture, the company’s earnings potential and what expertise he would bring, all while trying to soften his image of an impatient investor who likes to fire people.

“This is your company and you get to decide,” Ackman said, urging retail investors to vote their shares. “The decision to vote your shares is as important as voting for president of the United States,” he said, before showing a short tutorial on exactly how to vote for him.

The 51-year-old hedge fund manager is pushing ADP to cut bureaucracy, consolidate its real estate holdings and enhance technology, all to boost earnings. He is seeking control of three seats out of ADP’s board of 10.

Ackman’s effort to reach retail investors illustrates just how critical this group, which owns 28 percent of ADP, is in determining the outcome of the battle between himself and the human-resources software company at the Nov. 7 vote. Ackman’s $10 billion hedge fund, Pershing Square Capital Management, holds an 8.3 percent economic stake in ADP but has only a 2 percent voting stake.

Until recently, retail investors have been largely ignored in proxy contests, partly because employees, retirees and amateur investors are often seen to side with management if they vote their shares at all.

For Ackman, who has won and lost proxy battles, the stakes are high. While he has returned an average 15 percent a year over the last decade, his reputation has been hobbled by two years of double-digit losses in 2016 and 2015, and a number of prominent investors have pulled money out.

The importance of retail investors was illustrated on Tuesday as another activist, Trian Fund Management’s Nelson Peltz, appears to have lost his bid for one seat on the board at Procter & Gamble Co.

On the webinar, Ackman acknowledged mistakes like his bet on Valeant Pharmaceuticals Inc, on which he took a more than $3 billion loss when he finally sold his stake. But he spent more time detailing achievements at Canadian Pacific Railway Ltd, Zoetis Inc and Air Products & Chemicals Inc, and laid out the amount of money he and the two other board candidates have riding on ADP’s future success.

“We would have skin in the game,” Ackman said. He also said he is open to having top executives stay and would not envision large scale-layoffs.