The 29-year-old striker has scored 23 goals and provided 13 assists in 41 matches in all competitions this campaign, proving to be worth every penny of the £24million Sir Alex Ferguson paid Arsenal to sign him in the summer.
Van Persie is currently in the middle of a wretched run of form, though, having gone 10 games without a Manchester United goal, but regardless of his barren spell, Stam says that he's been an overwhelming success for the Premier League leaders.
"Since day one, when he joined, he has done very well," he told ManUtd.com. "Although I've heard people talking about him not scoring for a while, he's scored a lot before that and, when he gets chances again, he will score goals for United in the future.
"He's done exceptionally well and is a world-class player who has proved himself in England really well since he left Holland. So everyone has got a lot of respect for him for what he's done in his career."
Van Persie has been instrumental in Manchester United's ascent to the top of the Premier League table in 2012/13, with Ferguson's side currently sat 12 points clear of reigning champions Manchester City, even after Monday's 1-0 derby defeat at Old Trafford.
And, even when the talisman isn't scoring, his presence on the pitch benefits the rest of his Red Devils team-mates.
"Robin has been very important for the club," added Stam. "It's hard for strikers to score in every game and to finish off every chance that they get. It's not like that in football.
"The opponents always know the quality of the strikers so, if Van Persie is scoring, a lot of other teams will be marking him with two defenders and making it hard for him to score.
"But it doesn't matter as he's then taking a lot of attention away from the defenders and, if someone else scores, as they have been doing, then it's okay."