Its not so much that you can't use commerce in a multi site installation but there are issues to understand and think about.

If you want to use SSL (and you should in general and must in order to use Google Checkout or Authorize.NET), then you need to realize that only 1 SSL certificate can be bound to a particular ip address. So if you want ot have different hostname based sites with different SSL certifcates then you really need different IIS Web sites with different ip addresses. These sites can all point to the same installation folder though.

Its a little less problematic with folder based sites because they all have the same hostname and can all use the same SSL certificate.

The other issue I consider is who owns the data for the sites and do I want to mix different customer data in the same db. In some scenarios it may be fine but it means they all get backed up as one and its not trivial to make a backup of only 1 site or export 1 site's data if the customer owns the data.

Other than that I would also point out that our WebStore is in early stages of development, its usable for some purposes like selling downloads and taking donations but its not ready for general purpose ecommerce with shipped products and inventory tracking. There is no shipping calculations yet. Nor is it easily customizable. Its basically an alpha product that will change a lot in coming months. I am developing it first to meet my own needs and dogfooding it by using it to sell my own products. If people use it and have troubles they can provide feedback to help improve it but should not have expectations of it like it was a finished product.

Hope it helps,

Joe

Yes, all data is tied to a site.

The WebStore does support products and order tracking and even some reports and charts. It does not yet support inventory tracking, vendors, or wish lists.

There are as far as I know no third party vendors selling ecommerce store functionality that is designed to be integrated with mojoPortal. Part of my strategy for making mojoPortal more popular is to continue improving the WebStore until it does support general purpose ecommerce scenarios and its advantage will be how well integrated it is.

Currently I'm the only one I know of selling third party add ons for mojoPortal in my Store. There are a growing number of vendors offering support and services around mojoPortal and I think there are ripe opportunities for third parties to develop add on features for mojoPortal and I hope to begin seeing some of the DotNetNuke module vendors port some of their products to mojoPortal. 

I think the large community of third party module vendors is the only real advantage DotNetNuke has over mojoPortal. I do not think their platform is as nice to use or work with as mojoPortal. Many of the most popular add ons for DotNetNuke are for things we already have had built in for a long time like friendly urls and google analytics integration for example though I hear they are finally getting that in the new version.

My main criticisms of DotNetNuke are

1. It seems slow and it seems to consume a lot of server resources

2. Doesn't produce good markup. Its 2009 and DotNetNuke.com just now finally got their home page to validate against the w3c validator. Hard to find any other pages on their site that validates though.

3. Skinning is difficult

4. Accessibility is lacking, you cannot manage any aspect of a DotNetNuke site if javscript is disabled.

So they are bigger but I do not consider them better than mojoPortal.

DNN with ASPStoreFront might be a decent commerce solution but its fairly expensive.

You might also look at NopCommerce.

Best,

Joe