I upvoted your comment. According to the upvote calculator my upvote is worth $0.0043. @vagabondspirit upvoted as well. His upvote is worth $0.0008 for a total of $0.0051 .

That half of a penny is doomed to be wiped away as dust unless someone upvotes it with another penny and a half worth of upvote power.

You could save the dust with a self vote or dusty might save it for you. Either way, you are creating white noise on the blockchain.

As an account in the plankton, I've realized that my upvotes are best spent on root posts. Since I don't have sufficient SP; the upvotes I put on your comment simply created a dilemma for you.

Small accounts should engage in comments. They simply should not upvote comments that are likely to be below the dust threshold even when the comments are insightful.