You want to stay in touch with your customers and prospects, but which is better, an email newsletter, or a blog?

Business Blog vs. Email Newsletters: Which Works Better? - flyte blog: web marketing strategies for small business suggests:

When an Email Newsletter Is Better

If you’re selling something that requires some serious consideration from prospects, or that they may buy time and again, I’d look to use an email newsletter.”

In short, an email newsletter works for customers who know you, and are slowly making a buying decision.

OTOH, a blog is a way of getting search engine traffic, and building visibility with people who don’t know you at all.

Both are useful.