A friend of mine, Francesco Sanfilippo, just launched a new site, URL123.com, and he built it with ASP.NET. In the past, I used sites like tinyurl.com. Now that I have a Microsoft technology-based alternative, I'll use his site.
I like the idea of turning something like this:
[UPDATE] - I had to edit this post to wrap this URL because it was interfering with my right margin content.
As a consumer, I prefer to give my business to the businesses that give me theirs (or specifically, to Microsoft). That is, when given a choice between purchasing an item from Company A or from Company B, I'll choose the company that uses Microsoft software and technologies (especially online). I won't claim that I'm religious about it. I have to admit that here are times when I forget.
Back when I was looking for a site that could produce custom t-shirts I found CafePress.com, which was running on ASP at the time. I don't recall the name of the other company I considered, but I gave my business to CafePress because they were using ASP. A year or so later, they switched to JSP. The site went downhill and became unreliable. Before I could find an alternative, CafePress then switched to ASP.NET. During Beta. The site got better and they retained me as a customer.
Here are some other examples: