The 25-year-old, who joined last month on loan from Sheffield United for the rest of the season, has already proved a big hit with fans due to his direct style.
The former Villa whizzkid shoots on sight and Bilic believes Robinson has been a major factor as Albion shook off their recent wobble to secure wins in their last three league games.
Asked about Robinson's impact, the boss replied: "Massive."
He continued: "I don’t know how many shots he had (at Reading), what was it five? Six? That’s a lot. That’s why we wanted him in the summer also.
"He’s a direct player, he’s a winger, but he’s a winger that is always in the box, that’s what you want.
"When you have players like Krovinovic and Pereira who can release him, he’s very good at combining.
"He’s a big asset for us."
The boss revealed Robinson's knowledge of the Championship – as well as Albion's players – helped him settle in quickly at The Hawthorns.
"He knows the league, he knows the players," added Bilic.
"He played in this league last season. That’s why we wanted to get in January him, Kamil Grosicki and Lee Peltier, because in January you don’t have a pre-season.
"You have three days, or one week, and then a game. You want the players ready, so three of them when they came into training, they didn’t say ‘Hello my name is Callum, what’s your name?’ – they know each other.
"They only had to put the shirt on, we had to explain to them a bit of tactics, and that’s it. That’s why we got them, those players who don’t need time to adjust to the league, the training ground, the weather, the criteria of the referee.
"They know that in every game the opponent will have momentum.
"Nobody is that good, nobody is that bad in this league. They know that and that’s why they improved our games straight away. They’re good players."