There are a few questions any nonprofit should ask before agreeing to participate in this type of promotion.
The basic questions include:
- Is the website you are linking to offering fair prices and providing quality service.
- Is the website free of viruses?
- Are transactions secure?
- Does sending people to this website fit your mission. For example, if you are a neighborhood group trying to build a viable community, does it make sense for you to send customers to an online store for things they could buy in your neighborhood?
- What happens if your constituents or members have a bad experience on the site? What happens if you got the wrong answers to the first three questions?
- Does the income you receive justify distracting your website visitors with this link? Could this promotion reduce the number of people who click on your "donate now" button?
Slightly related to this is a column in this month's Fast Company: Do Something: Jurassic Park Syndrome by Nancy Lublin (I really look forward to her columns). She talks about some trends ins cause marketing.
Note: I owe the term "Give Us Your Membership List" business plan to Tim Mills Groninger. He coined it a few years ago during a National Nonprofit Technology Conference (link to this years NTC) .