Actually I think I might have gotten 1 or 2 curie upvotes in the last 2 years ;) ocdb was a lot more common though. It's taken 2 years until I slowly have the feeling that I am getting some meaningful rewards, and even so it's not so much. Here are some tips:

-buy steem! For only a 100$ you can get almost a 1k steem; I don't expect it to be this low too long
-with more steem curation gets better and better; I make about 10 Steem/week with curation
-Don't just curate small accounts, you have to balance it with the large ones
-Use @steemvoter for automatic votes
-And the most important thing: have perseverance. It takes a long time to climb the ladder, but if we help each other it's so much easier.