They see you as someone who really wants to help them, whether it is free tips and advices or recommended products/services that could enrich them. So you should start by sending them good information for a certain period of time and then start sending them separate messages with embedded links to products and/or services. As a rule of thumb, you should only send out such promoting messages for each third email, to the addresses on the list.

You build up confidence with your subscribers because you acting a little reserved and not bombard them with so-called "buy now" messages email list every time. No one likes to receive a bunch of such mail every day and they are likely to be deleted. If you treat your subscribers well, you'll be plenty rewarded. Good treatment of your list members involves giving away free reports, articles, tips about good links, resources and more.

Give them this once a week, every second week or once a month. This gives them a good reason to open the emails from you. They know you always give them valuable information whether it has to do with a request for a purchase or not. And by giving them free "products" now and then, they'll feel safe with you and you can more easily enforce a sale when you recommend a product or service.