Indeed, I saw you managed to already make it work by offering a good ROI. It's not always easy to get a delegation filled at a reasonable price and if more users try this strategy the harder it will likely get. That said, you should see your curation reward % go up with a higher upvote (https://hivestats.io/@okarun) to 8%+.

From what I understand, there is a threshold on Hive post payouts lower that 0.02$ get burned. So if you were to upvote a comment and the user doesn't use a service like @dustsweeper (which you should do) if will have been a waste of an upvote and lower your curation rewards. Also, upvotes under the threshold don't get shown in the mentions (at least on Hive.blog) which makes it harder to get noticed.

That's why I aim to have at least around 3000 HP leased. Especially if you are active on Hive and if you want to grow, Leasing some HP should really be beneficial.

Good Luck