Collecting feedback for small businesses can be very different from collecting feedback for nonprofits. However, in general Email Blasting Services will help you with this, and there are several low-cost options. Check out the links below to see all of the features that these services have, such as providing you with email templates and preventing your emails from going directly to your recipients' SPAM folders. These tools also have lots of reporting features for figuring out open and click-through rates as well as unsubscribes and bounces (what are these things?). Groundwire has a comprehensive Email Service Provider Comparsion Report (2010) that reviews the "top" 10 ESP's and includes pricing information for each.

Some Affordable ESP's:

• Vertical Response is free for US nonprofits for up to 10,000 emails per month
• MailChimp is free for anyone for up to 2,000 subscribers (or 12,000 emails) per month
• Constant Contact is low-cost and offers a free 60-day trial
• Check out Matt Garcia's Popular Bulk Email Tools on Social Source Commons
  

For an even more thorough analysis, you should consider a using a CRM (Constituent Relationship Manager), but these take more time and money to set up. Some affordable examples are Democracy in Action and SalesForce (free for Nonprofits).

For additional resources and articles, check out these:

• Reliable, affordable ways to send out email in bulk, TechSoup
• A Few Good Broadcast Email Tools, Idealware
• In Search of CRM Part 1: Understanding Constituents and Processes, Idealware