Keeping tabs on your customers can make the difference between a good year and a great one. Who's ready to buy? Who needs more coaxing? And what sort of cajoling has worked in the past? Customer relationship management, or CRM, software can answer these questions by tracking interactions with customers and plotting future tasks. Here are two of the best free CRM software programs on the market.

SUGARCRM

The dominant player in free, open-source CRM, SugarCRM has an active community support forum -- which is great, because the free version lacks tech support. Software developers have created cool add-ons; one allows you to check customers' Twitter updates. SugarCRM is also adept at pulling customer data from social networking sites. The paid version starts at $499 per year for up to five users; it includes cell-phone access and an offline mode.

ZOHO CRM

Zoho is entirely Web based, so it's simple to set up and use. (The free version of SugarCRM runs online, but you still have to download and install some complicated code.) Zoho CRM also integrates seamlessly with other Zoho programs, such as e-mail and Web conferencing. If you have more than three users, you will need Zoho CRM Pro, which includes e-mail marketing features and runs $12 per user per month.