Thank you for your comment, Ngans.
Before I came here I thought it was really all about quality content and "democratic" upvoting. It's a little disheartening to learn it's not (only).
Yes, I guess it is very hard to get noticed without using bots. However, I'll still not use them as I am too convinced it's not right to pay for votes. I hope these instruments will be banned / their use will be rigorously flagged soon.