I decided to participate in the campaign because @Murat said that people could only participate before June 8, and by June 8 only 10 people participated in the program.
I have also joined that, and I am not removing the signature as there is no open campaign. I will stay on the campaign until there is a good campaign. In this time LEDU will get free promotion from me.
However I realized the principles had changed, people could join after June 8 and they still accepted 50 participants. If the campaign has 50 participants, each person can only receive more than $ 10 per month, which is a very low payment.
You are right even some one can join at the last phase of the campaign and create a lots of post which might be good for that person but that will not be good for other participants and also will not be good for the project as they will wear the signature only for a little time.