Founder: Delicious Copywriting. Marketing consultant, copywriter and conversions expert for the biggest names in health, wealth and relationships.
Matt O'Connor has generated tens of millions of dollars in sales for leading entrepreneurs, start-ups and direct marketing giants.
His clients include Agora, Aweber, Bottom Line Publishing, Athletic Greens, Real Dose, Ramit Sethi, John Romaniello and Neil Patel.
A lot depends on the service you're offering.
But I'd definitely include case studies of previous clients. Don't just offer testimonials but weave a story around your previous clients' experiences.
Again, I could help more if I knew what you were offering.
Another useful strategy is to offer some kind of special/limited deal on your service if they still don't bite after x amount of emails. Just be sure to move people from your autoresponder prospects list to a buyers list when they do eventually try your service.