If you are looking to provide a DesktopWidget solution to individuals with whom you interact you need to provide something that they will find of use. Unless you do then you will not achieve the branded desktop presence which is so important.
What you provide them with is likely to depend on the type of business you operate and who they are. The flexibility of DesktopWidgets solutions means that you can be sure that the solution devised will add value to the recipient's desktop because you can give them what you think is appropriate. This substantially increases the likelihood of achieving the branding and the message you want to deliver.
You may want to offer a tool that is of general use such as a calendar or desktop notes. People always find these tools useful and allow you to provide a message and brand which is subtle and doesn't detract from the value of the tool.
If you have a relationship with the individual you may be able to add value by offering a solution that is more personal and makes this relationship more efficient. You can provide information on the latest offers you have with links to get more information or purchase. You could give the user a tool to record the items which they need to purchase from you which then links to your website to purchase the items. You may simply find that a tool that allows the user to search for items on your site.
Remember that DesktopWidgets not only deliver added value to others, but also to your business. By making interaction with others more efficient, you can increase sales, improve customer relationships, all whilst reducing costs of doing these things.