Give your username and private posting key(obtained from wallet in your profile by clicking show private posting key)

Why do you need a private posting key, if the goal is to give upvotes? I mean i can clearly see that both you and @aggroed are positive members of the community and obviously not scammers, but let's look at this post objectively:

1- You promise free upvotes to people
2- You ask for their private keys without explaining why they are needed
3- You don't even mention how those private keys will be stored
4-This is adressing minnows who are the most vulnerable to scams and don't necessarily undersand how important it is to keep the private keys private.

As I said, obviously you yourself aren't a scammer, but you definitely reproduce each point of what a scammer would do in order to gt access to the private keys of abusable users. At the very least, it should be mentionned that giving up your private key is not a benign thing to do, and that you should assume the consequences of such an act. You do the exact opposite and make it look like a completely benign thing to do, just as any of the other steps. In this case, since it is only the posting key, a person with your key can post, comment, vote, follow from your account. It would be for example extremely easy for them to destroy your reputation, by posting illegal/insulting comments or posts.