Douglas Sherrets of Minority Rapport, a blog about social networking/user generated content - think FaceBook, MySpace, MyYearBook, Jambo, etc. - e-mailed me the following question: How much value do you think is added to the user experience of shopping engines when you are logged in versus not logged in?

Here’s what I had to say:

Depending on the shopping engine, there is a value to registering/logging in. Almost all engines have basic features for registered/logged in users such as the ability to save shopping lists, get special updates/announcements, and leave reviews. In addition to these basic features, some of the engines have ‘advanced’ features:

Froogle - There is a feature called ‘Wish List‘ wish enables you to share your shopping list with friends and family - esentially a very basic gift registry. If you’ve registered, logged in, and created a wish list, anyone who searches for your email adress on Froogle can see your list.

PriceGrabber - There are two features here which I find interesting. First, ‘Price Alerts’ allows you to set a target price and be notified when a product is available below your target price. Not as elegant a solution as an RSS feed, but good enough. Second, ‘BottomLine Price’ allows you to see if it’s better to buy a set of products from a single merchant or multiple merchants.

Yahoo! Shopping - Similar to PriceGrabber, Y! has a lowest total price feature. Like all engines Y! offers the ability to save products/create a wish list, but Y! gives enables users to add notes about saved products and easily email the products to a friend.

As you can see, nothing groundbreaking, but definitely some useful features.