Good mailing list service to get started with a free product

Hi. I'm currently working on my first product. It's almost done, and that makes me very excited. I'll be sure to post about it when it is done.

My product is completely free and targeted at developers who like to go to conferences, and I hope to make a little side-income by advertising for other companies in the same space on my mailing list.

I'm not sure what product to get started with though. I'm looking for something that can be embedded on a website as I'm launching without a back-end. I plan on doing more back-end things if enough people are interested in the product.

Ideally this product offers quite a bit of free subscribers until you need to start paying for the service. Mailchimp, for example, only goes up to 2000 free subscribers and then it's like $50 per month, which is too steep in my opinion and I don't know how many subscribers I will need to start making some money with the mailing list.

I'd love to hear your suggestions and experiences. If you have a mailing list service yourself that's also fine :)