As we know, it's hard to join a bitcoin-based signature campaign posted in the "services" section. As seen, there are plenty of altcoin bounties that most forum users are trying to participate. Can you say that these campaigns are profitable? Or have you had the chance to join a signature campaign (altcoin bounty) that you found very lucrative in the past?
I will prefer you call the altcoins campaign as bounty campaigns and not signature campaign, determining the profitability is base on user's experience and approach to it, some may find it demanding enough than it offers while many really like that and finds pleasure in it alongside the pay rate, i will only advise you to read the rules, apply and consider the fact by yourself if truly worth going for or not and not to just conclude on someone's else experience.