Wait wait wait, with 3 different accounts??? How can you handle that, and how about the limit post/ip???
And, is it legal
In theory, nothing stops you from having multiple accounts in this forum (it isn't against forum rules), and using them all to join signature campaigns. In practice however, there are a couple of limitations, I suppose: as you mentioned, handling several accounts and posting with them all is probably time consuming, and will likely get you banned, if post quality is poor; and some campaign managers don't like that, and will deny you payment if you get caught doing it.
So we can just use multiple account with our own risk to get banned or anything
You can try to get into a campaign with multiple accounts but I wouldn't recommend that since it's against the signature campaign rules. Try to play fair and only use 1 account for signatures campaign, it's worth the risk you can earn more with 1 account than multiple accounts and get banned.
I agree. I didn't even know multiple accounts for posting was a thing until I saw them being sold. I can only see sense in buying them if you need to "level up" yourself or buying it for somebody.
Being fair is better for you own profit, you won't have a risk of getting banned, you earn more and don't waste much time. All over it's better to just use one single account for your signature campaign participation.
As far as my knowledge about the forum rules go, account farming isn't strictly prohibited. Actually, it is stated in the Forum Rules:
18. Having multiple accounts and account sales are allowed, but account sales are discouraged
https://bitcointalksearch.org/topic/unofficial-list-of-official-bitcointalkorg-rules-guidelines-faq-703657So that means that you can create multiple accounts, post using multiple accounts, and join signature campaigns with multiple accounts. As long as you abide by the forum rules, you haven't got anything to worry about (though I'm not entirely sure about joining signature campaigns with multiple accounts. Better ask the staffs and mods).
what about dev of signature campaign, recognize your style of writing? you could get a negative trust besides the ban, not worth it i think, or you should be really careful if you want to do something like this, it's not that easy especially if you run more than two(like 5-10)
Creating multiple accounts and joining a signature campaign is kinda dumb if you'd ask me, because honestly, joining in a campaign that is a pay-per-post and doesn't have limits on posting is already a good campaign. Why bother creating multiple accounts and post simultaneously and switch whenever you feel you're done? That seems to be wasting a lot of time. Also, I can see users earn to almost half a bitcoin every week.
I agree with what's been said. It is not worth it, having limitless campaigns like Bit-X any posting you could do with another account could be done with your main account. So why bother?
True. Why bother creating another account when you can do the same thing in your main account and earn more by focusing in one and only one account? Switching between accounts is a waste of time for me, and you are also taking advantage of the offer, which I think is pretty unkind.
I agree with what's been said. It is not worth it, having limitless campaigns like Bit-X any posting you could do with another account could be done with your main account. So why bother?
Indeed. One should play fair though. People have been given a great opportunity with the signature campaigns. Their lack of self control and greed is what makes them either make multiple accounts or spam to take advantage of the offer.
A few posts will reward you with more in addition to taking less time than using faucets.
Welp, people can easily be controlled by greed. That has been proven by history a lot of times. As long as there is an opportunity, people will try to take advantage of it.
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Why make yourself look cheap when you can earn 20x of the amount you're earning after a very short time? I don't advice you to leave the campaign but I think wearing signature in the very early stage doesn't give good impression to other people, especially during trades. For Eg: You are selling a good for 1 BTC and you are a newbie wearing a signature. This probably won't make a good impression to the audience 
