I checked their signature spreadsheet and they don't have a lot of participants and why is that? they have an amazing +20 points per week if you wear their avatar and a referral program that can give you 20% of your referrals points as bonus to you.
Tachain is still not well known. Also from the bounty campaign you hear very little. It will probably take some time before the signatures find more participants. For those who have been there from the beginning, this is of course a great thing, they get more stakes :-)