For me, I'll go with signature campaign because it seems more efficient and attractive to the applicants as well. Here are the reasons why (IMO):
1. Since the payment is in terms of btc, the participants are never worried about losing its value (unlike alts/tokens). Hodling it for a long time or spending in an instant were not a problem.
2. Since the payment are done weekly, the participants can be able to save more time and effort assuming that the ICO they're advertising was a scam simply because it's easier to mitigate. In short, they feel more secured.
3. There's a greater quota, usually 25-30 posts per week compare to bounty only having 15 posts. Meaning, much frequent advertising within a week which is favorable for the developers of course.
Furthermore, to ensure a succesful campaign, choosing a campaign manager is also a factor to be considered. You should pick the one who's punctual (from updating the spreadsheet to sending of payments), always approachable for case of queries and strict to implementation of rules but still reasonable. Thus, considering yahoo62278 or Zapo would be a great choice. Good luck
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