An effective way of marketing to an established set of customers has for a time been mass marketing via email. You should always encourage your customers to include the email address when they register. If you include clauses (with opt out buttons) that let you utilize 3’rd parties it will increase the value of your list. Be careful though, you don’t want it to be a list of people that has banned you from sending to them.
Genuine offers are required. And they will feel extra good about it if they receive it before everybody else. Like sending the email the night before the general release of the offer.
How to send to this list you have collated is a matter of choice. If you are a regular mailer with knowledge of emailing I would recommend a self run packages due to its lower cost in the long run. It also leaves you in control of the list. A list that can have a value in its own. If you contract out, be careful to have clauses in the contract that expressively say the list of email addresses is yours and yours alone, and is to be handed back if the contract ends.
A good one for self hosting is Listmanager form Lyris http://www.lyris.com A very high capacity and fast mailer with response tracking facilities. Couple of hundred thousand an hour should be no problem. It also handles spam filters very well. An important consideration for repeat mailing. You don't want all your efforts to be filtered away. A problem with free and cheap mailers.
Lyris also has good support.
Lyris also has good support.
Always send from a domain that can be looked up via reverse dns. This is the first test from most filters. Also set up a real reply address where you can handle automated verification responses from spam filters, and answer spam complaints from the likes of gmail. Be careful with having a opt out link at the end of all sent emails.
You need to carefully monitor your sending’s. A good system should track the progress and put non successful conversations on hold. However a general problem in the transfers can lead to a list where all is on-hold. See to that they are not wiped off your list to quickly. I would also recommend subscribe confirmations via email to verify genuine email addresses and sort out the mischievous.
Integrate your emails with your website so you can track the responses and uptake/sales from each mail. A good package should have this included.
Creating a regular stream of similar emails can be a chore. Some packages also offers automated help with the composing of the emails, allowing a daily marketing becoming somebody’s part-time job.