At the same time, I can only join one project, but I can join 2 types of campaigns. Like signatures and Facebook or Twitter campaigns at the same time and in the same project. I think Twitter and Facebook are not so heavy in their duties, and I also still have free time from my assignment during the signature campaign. So at that time, I used to join another campaign to make more money and profit.
Well when I started, i used to concentrate on one particular Bounty projects, but when I realize that there are so many exciting ICO projects out there that have what it takes to succeed. I decided to participate bit by bit. Now I can run up to 4 projects effectively while carrying out different task in the campaign. I think the stress isn't much if you are used to it and I also think the stress is worth it especially if you're participating in signature, translations and some other campaigns that have High percentage of token allocated to it. You can give it a try.
It's our duties to participate in campaigns such as bounties, facebook ,twitter and etc. We're the one who would like to choose which reliable to us and in my choose is only bounty program in where it has a bigger allocation to distribute tokens. It's more stressful for me to join another campaign so I only focused in only one program.