Interesting calculation, and i like numbers that i see 
. I don't like in countries of 3rd world, but i work as a security guard and i earn around 300$ a month. So in my country it would be awesome if i could start earning that 1300$ per month . But sadly it would be near impossible to have 7 accounts in 7 different signature campaigns, and if i remember correct it is against the rules to have more than one account in same signature campaign. But still its nice just to think about that 1300$ .
Forget it, really. Although the numbers may look good on paper it's nearly impossible to get close to that due to several reasons. . I don't like in countries of 3rd world, but i work as a security guard and i earn around 300$ a month. So in my country it would be awesome if i could start earning that 1300$ per month . But sadly it would be near impossible to have 7 accounts in 7 different signature campaigns, and if i remember correct it is against the rules to have more than one account in same signature campaign. But still its nice just to think about that 1300$ .1. Post has to be of certain length to count, which makes spamming difficult
2. Managers are monitoring the quality, so if you constantly post nonsense you'll get permanently banned and end up on smas list.
3. 2000 posts a month means that you'd have to squeeze out 66 posts a day, which might not be a lot if you wrote short, low quality responses, but will end up being incredibly tiring if you actually put some effort into it. I usually get bored with the forum after writing 5 or 6 posts, 66 requires a lot of effort and stamina.
4. It's hard to find a well paid spot nowadays, so it will take you some time before you can fit all your accounts into the highest paying campaigns.
5. Daily spamming with 7 accounts will get you caught and banned sooner or later, so my prediction is that you'll spend months levelling them up, write for a month or 2 and lose them all. Is half a year of work worth 2 BTC?