It's a lot more fulfilling to be a Legendary member or something & earn fairly well by making 50-60 posts a week. Legendary members can earn maybe over 4 bitcoins a year from a sig or avatar campaign.
It's not a huge amount but if you're working too it's a good little side earner .
If bitcoin goes to the moon those 3 or 4 bitcoins you're earning from a campaign simply for posting on a forum fairly regularly could buy you a new car or be a deposit on a house? It beats farming Full Member accounts for 0.2 bitcoin or something surely?
I mean how many is it possible to do at one time & is it financially rewarding enough to bother?
Just my personal opinion, obviously people are entitled to do what they want.
People don't just farm Full Members. You could farm Ledgendaries if you had enough dedication. And it can be worth it for all the reasons you just stated especially if people are willing to put in the time and effort and people can join the signature campaigns with multiple accounts rather than one and maximise their earnings.
it need a lot of dedication(which mean plenty of time, that can be used for posting with your main instead of wasting precious post on the offtopic board to increase your fresh newbie account), though, not many are doing it, otherwise no one will buy, this is certain
and if you are in a campaign with no limit, it makes less sense for you to have multiple account... actually it make no sense at all
also in the time required to build a legendary account, you can earn like 30 btc with signature campaign, at least, when with a mere legendary you could earn at best 1 btc(they are worth more but i think none right now is willing to pay 2 btc for it)
so basically you need to build 30 legendary at the same time to match one good hero, that is farming with one signature campaign only