The Tykes upset the Baggies 3-1 to secure a third win in six matches under Robins, who succeeded Simon Davey earlier this month.
Robins said: "I'm greedy. I want more than what we saw on Tuesday. I want a better performance and I'm looking for improvement.
"We have to reach that level on a game-by-game basis. There is still a lot to do but the team are enjoying playing and we have to maintain that."
The former Rotherham boss added: "We are not on a high now after Tuesday. You have to take the positives when things don't go to plan and confidence when they do and beating West Brom did give everybody a boost."