Palace moved off the bottom after their midweek victory against West Ham in Pulis' first home match in charge - and are preparing to welcome Cardiff City to south London on Saturday.
"If we don't win games, we mustn't lose games," Pulis said. "That is what Cardiff have done, they have got four more draws than us. It is getting every point.
"When I first got promoted, I can remember talking to a very experienced Premier League manager who said to me goal difference is vital.
"It is an extra point at the end of the season, that is how tight it is in the Premiership at the end of the season.
"Teams have gone down and been relegated because of goal difference, never mind that single point.
"So you are fighting for every crumb on the table. We're sat at the top table and we're at the bottom of that, but we're sat at it.
"You have to work for everything and make sure that everything works for you."
Marouane Chamakh is a man who has struggled to adapt to life in the Premier League but Pulis is a big fan and has urged him to build on his match-winner against West Ham on Tuesday.
"He has been fantastic in the two games we've played," Pulis added.
"We watched him at Bordeaux when he had that very, very good season before Arsenal took him and he looked a top player.
"He did well initially at Arsenal, but he has just lost his way and people do that.
"I've only been here and watched the team in three games and three games don't determine whether he is going to be the right one or wrong one for us.
"He has got to keep doing what he is doing, and if he does that then brilliant."