another thing I need clearing up!

The problem with them is that people sign up to be able to send out their ad but don't actually want to receive ads. So your ad is going out to a bunch of people who likely will never even look at any ads they receive.

This is kind of your second question today asking advice on whether or not becoming a spammer is a good idea.

It isn't!

It really isn't a good way to build a business.

I don't think it is worth it. First, the subscribers (if they are real subscribers) are (probably) not targeted to the product/service you are advertising. Second, I wonder how many of these people will actually get your email? Depending on the software or service you are using to send these emails, you might find that your email blast might not make it past most spam filters. Third, email blasting people with an offer or two is not a good way to build an income stream online. How long do you think you will be able to (spam?) these people with offers and how much of them do you think enjoy receiving intrusive ads about things they may or may not be interested in?

If you want to run a successful email marketing campaign, choose a niche and find a problem within that niche. Offer the solution in return for a subscription to your email list. Build your email list in this way. Continue to use your email list to communicate with your readers. Build a relationship and provide quality information for free (information that your subscribers can benefit from). When you have a sizable following, introduce your own or someone else's product into the mix. That is when you will make a lot of money.

Thanks for your answers, I'm new to building a list so quite naive to it! The last thing I want to do is spam and have no intention of doing so, that's why I asked the question! and do appreciate your answers.