ICO and IEO are for raising funds, what about bounty? To create awareness around the web to get more investors right? This makes it two ways for projects to gain investors, I would have said ' why do new projects need bounty hunters for then' but bounty hunters are playing a big role here as you can see that's why we keep seeing bounty campaigns from IEO projects, although not all of IEO cares about bounties
Bounty on a project is free, because there were also many successful ICO projects without bounty and now there is also a successful IEO project without bounty, meaning that bounty is a policy of the dev in an effort to expand the promotion of the project, so it can be done and it can also not be done, you can prove this by visiting some popular exchanges and several cryptocurrency sites that are already popular, because in the crypto and exchange sites that are already popular there are many new project advertisements that do not have bounties in bitcointalk.