Curating is mainly about spotting good articles and upvoting them. Preferably before others do (that maximizes the profits). A percentage of the article reward (25% IIRC) go to the curators in order of vote priority and vote weight. If your vote doesn't have much weight then obviously curation rewards would be very low. My ~1500 SP give me ~3-10SP per week from curation, but I'm not very active in that regard and I use a lot of upvotes as "likes" in comments (which isn't really maximizing my curation potential). It could probably be twice that.