I think this is the best way to promote ICO project, because in the forum your signature can seen by crypto lovers, investors and etc related with crypto, and signature campaign required experienced members with at least Jr. Member to join the bounty, so the ICO project isn't seem like low quality project because the project promoted by experienced members. You can imagine to put yourself at the position of the developers and bounty manager, would you pay good members with high requirement with low payment? I think no.
and how about you as the bounty hunter? do you want to receive low payment but you need to work hard to make a quality post? that different with another campaign like social media, telegram and etc, that just need promote the ICO project just by report the original post and sometimes need to make an original post at your social media account, that easier than Signature bounty campaign.
I hope you can imagine about this.
thanks