This question seems obvious, of course you want your customers to have a personalized experience on your website…especially if you’re selling products that might be of interest to them in the future. However, not every customer shops in the same manner and not every customer offers information (birthday, anniversary, etc.) to allow you to know them better. Not to mention customers often purchase gifts online and don’t need to be reminded of reorders when the gift was a one time purchase.
This blog post by Paul Boag is very insightful and points out the pros and cons of personalizing the ecommerce experience on your website.