Is it possible to hold the funds on an escrow for the first week of the campaign so participants will not be afraid to join?
It's a good campaign however it's a bit suspicious since you are just starting and you are using brand new account , it really help if you can hired an escrow for this.
If you have gone through our campaigns, you will understand how are we different than others. Participants are not required to perform intense activities for a week (and then we pay) so that they should be afraid of losing their work. Its just 2 shares/retweets per week! Besides, we already ran these campaigns and distributed rewards for a whole month without promoting here. So, you guys don't need to worry about payments at all!