A strong email database is one of the greatest assets you have in your marketing toolbox. An audience that is engaged and eager to listen can be the thing that pushes your organization to the next level.

Some statistics say that an organization’s email database will shrink by 25% every year. People’s interests or jobs will change over time, their email addresses change, they will opt out of your list, or they will pay little attention to that free service email address they only give out to when signing up for lists.

Not only is marketing to the remaining 75% of subscribers super-important; you should also always be working to replenish that disappearing 25%.

We’ve compiled some helpful Dos and Don’ts to remember as you work on growing—and maintaining—your organization’s email list and database.

DO collect names whenever possible. When people call your office to ask questions, ask them for permission to add them to your email list so they may receive updates and information. Keep paper and pen sign up forms at any table where the public interacts (front lobby area, on the table at events, etc.). And always include a newsletter sign-up form on your website's homepage.

DON'T use the collected names to bombard with requests for money. Make sure you send your list helpful information and news about your organization.

DO build a relationship with potential subscribers. Make sure you are active on social media, offering incentives for people to sign up for your email list. Facebook has recently installed a “call-to-action” button in the header. Create a helpful whitepaper or small ebook for your audience. Use the “Sign Up” option on the FB call-to-action button to send people to download the special offer and sign up for your email list.

DON'T just take, take, and take; make sure you give more than you take. What’s the best way to turn off potential subscribers? By placing constant demands on them, your readers won’t like feeling as if they are being “sold.” Share stories, offer freebies or exclusive offers or share opportunities. Sell sometimes, but in the context of being helpful and entertaining.

DO be creative with interesting ways to add new subscribers to your email list. Because an email address is something of value, you need to offer your audience something of value in return for their personal information. Offering free downloads or creative promotions such as photo contests or online games are a great way to incentivize people to sign up for your list.

DON'T neglect your website’s real estate in its effectiveness to attract new subscribers. As long as you are writing consistently helpful content, your readers will want to stay connected with you. Make sure your About page features a sign-up form, and place one at the end of each blog post. You should also have a sign-up form in the header throughout your site.

According to the 2014 M+R Benchmarks, a study featuring statistics about online fundraising, advocacy, and list building from 53 leading nonprofits, the average email gift size was $57 (one time) and $20 (monthly). So, doing email marketing right is important for the longevity and viability of your organization, and the more engaged audience members on your list, the greater your results. Constantly seek out ways to grow your database and build relationships by consistently sharing valuable content with your lists.