Rather than spending thousands on CPA campaigns which might not give you any customer at all go with usual advertising campaigns. If you are from ICO marketing team launch bounty campaigns, buy some PR article in big crypto based media platforms and hire someone who have previous experience with ICO marketing.
Thanks for your advice. It seems that bounty campaigns look the most effective and most ICOs now use them for promotion. We are just preparing for our pre-ICO and does it make sense to tell people about our bounty campaign before pre-ICO or should we do it when we start our pre-ICO? Thanks!