I think social media campaign bounty programs are good and effective as they are possible and easy ways to educate people with zero knowledge about cryptocurrency. Through this means, many people are convinced about d crypto world and there after show their interest in it, it even provide insight about that project you are into and how it works.
When we do talk about bounty program then most likely project owners would always target exposure and possible to hook up with possible investors. We do know that social media people or traffic doesnt really have the good rate of people who are aware of crypto which means it doesnt really make effect and why we do see token allocation is smaller compared into other bounty program.Casual people would able to see crypto related things will usually neglect unless if his/her curiosity will be provoked then he might engage as well.
There's actually quite little research available on effectiveness of social media campaigns - but you also need to consider what is deemed effective. If the campaign's aim is simply to promote awareness of the project, then this is typically achievable by this method: content is pushed out to new and diverse audiences. The more reputation and credibility owned by the social media owners, the higher the conversion (of readership at least).
There is a definite correlation, however. The more successful ICOs have had huge social media followings, with their own followers also promoting well the brand and ideas to their own audiences. Perhaps in time, metrics will be more easily obtainable, as people become more crypto aware, audiences are more likely to engage beyond their first exposure on social media.