Free as in - it doesn't cost you anything financially/reward wise. In fact, upvoting earns you curation rewards, so it's actually somewhat of a profit - even if small.

Both RC and voting mana replenish in time. Even SP is 'free' in the sense that, it doesn't 'use up' you STEEM, just locks it away.

Ok @steemincome, I just don't think spamming up people's comments promoting the service, that mimics a well known service, is a good thing. You should just be commenting like a normal user - based on the post content, and people will notice you that way by just normal networking and word of mouth, without the need for spamming, please.

Hmm.. Maybe I will give you a try some day. Wouldn't hurt to have two STEEM incomes supporting me ;P