A good email campaign is a tried and trusted method of letting your friends and business associates know about your website.
Avoid buying email lists and spamming strangers and this is both rude and a nuisance to others trying to use the world wide web.

If you want to have a newsletter or periodical update for your customers, you could use an 'opt in email' system whereby each user gives your website permission to send them an email every week, fortnight or month etc etc
This allows the browser (user) the choice wether they want to be contacted again in the future.......your essentially putting your customers needs before your own.

An email campaign can be done without the need of a web developer like myself but if you need more services in this area, I am near at hand to assist you.