I don't understand how the fact I think signature campaigns are useless as a marketing tool and the fact I'm wearing a signature shows some kind of hypocrisy or inconsistency. I don't have to believe that signature is a good advertisement to wear it. But I have to admit that "useless" is not what I meant to say. I rather think signature campaigns aren't worth money people spend on them. Hundreds of thousands of dollars are spent to promote dozens ICOs on one particular forum (even the biggest one) - I don't think it's beneficial enough. Personally I know at least two ICOs where devs just don't want to pay for their bounty campaigns (but they probably will have to do that) just because they got almost nothing from them and have to pay a LOT of money.
Nevertheless I try to promote projects I like in the case I'm wrong about all these bounty campaigns so no hypocrisy or inconsistency at all.
They are effective, but not as much as they were a few years ago. The forums become to saturated with adverts that people are simply automatically skipping them in their mind. It happens on websites that you visits and the adverts are there, but you never really read them or take notice. It's one of the reasons why stickies are often ignored in the forums.
A few people claimed a while back that they could live off the referral links that they had in their signatures, but if they were to try that in todays market it likely wouldn't yield the same results.