You can promote CPA offers that need leads from the USA by targeting US-based audiences. You should use ad platforms like Facebook and Google to reach them. These platforms allow you to focus on specific locations like the USA. You need to create ads that appeal to US users. You need to use geo-targeting to narrow down your audience. You can also run email marketing campaigns targeting US subscribers. Social media platforms like Instagram and Twitter work well for reaching the right audience in your niche. You must test different ad creatives to find what works best. Consistent tracking and optimization will help improve results on the long term basis.