I am considering using SharePoint to house all my content for an eCommerce website. I plan to use .Net components and services to relate the data and perform functions. Is this a good idea? Or should I look elsewhere for this? The reasoning behind it is that my company doesn't want to purchase a CMS and we already own a license to SharePoint.
I've put up several internet-facing sites that all used SharePoint's CMS features and all have worked out very well, however SharePoint's eCommerce support is simply not there. If you are just putting up a catalog with pages to support products/services and shopping links that point over to a full-blooded eCommerce system, then SharePoint can handle that easily. However, if you are looking to somehow have SharePoint handle the entire eCommerce side of things, then you will be sorely disappointed. SharePoint has no out of the box eCommerce support whatsoever and the only product in Microsoft's bag of tricks for this is Commerce Server, which I cannot recommend to anyone as it is, shall we say, "quirky" and barely documented.
The best approach really is to assess your actual CMS needs, then your eCommerce needs, then identify the places where there are crossovers, like promotions and sales and hammer out those requirements as well. Once you have a list of what you actually need, you can compare that to what is out there.
FWIW - if you do decide on SharePoint, you might want to make sure that your company has the right license for using SharePoint on the Internet as it is a special one.