In terms of what many vendors call unlimited service, Web Hosting Pad's terms of service indicate that its definition of unlimited is what it calls "incremental." Basically, as you need more capability, it wants to discuss that with you, both to help you get the most out of its services, and to make sure you're using its systems without abusing them.
Aweber and GetResponse. Technically you can make any email autoresponder service work, but you'd have to be strategic about it if you are doing Affiliate Marketing. I've heard so many unfortunate stories about other providers closing peoples accounts due to affiliate marketing. However, Aweber and GetResponse have been more supportive of affiliate marketing and are currently the safest choice if this is what you want to do.
If you want to integrate your email with your shopping cart but don’t quite want to spring for InfusionSoft, 1ShoppingCart could be your answer. 1ShoppingCart is a one stop solution for payment processing and email marketing. It allows you to segregate lists and mail only buyers or your entire list. It’s one of the more reputable shopping cart services on the net.
Shared hosting is web hosting in which the provider houses multiple sites on a single server. For example, Site A shares the same server with Site B, Site C, Site D, and Site E. The upside is that the multiple sites share the server cost, so shared web hosting is generally very inexpensive. In fact, you can find an option for less than $10 per month.