in 2017 bitcointalk signature campaign is on its top performance, many investor looking in to our signature to define where to put their money. but so many scam project or failed project. now it is still useful for link building for your project because bitcointalk is the oldest forum for crypto related. and this is why i am still and still reading new reference from here.
I believe that it's the bounty campaign who is prominent at that time since every projects at that time has gotten its value rising after being listed on an exchange. Bounty campaign slowly degraded after it enters the bear market where more and more project has become a scam and bounty participants lose their will do join knowing that they can't gain something from it. Signature campaign is average at that time but big gainers comes from bounty campaign as far as I remember because I joined some bounties.