It's absolutely fine. As it's the mechanism for attracting a wider audience to s...

darrhiggs on Jan 20, 2013 | parent | context | favorite | on: Ruby: Singletons, Threads, and Flexibility

It's absolutely fine. As it's the mechanism for attracting a wider audience to something that benefit is being derived from, reminding them to up-vote the article seems mutually beneficial. You are not forcing anyone to do it.