I have touched base with every one of my customers that bought something from my mini sites. The majority of them liked the fact that they could go to a site that sold something they were looking for and buy it all from one simple, small site. The others just did not have an opinion.
One thing that I have found most mini site designers to agree with is when designing a mini site - keep it mini. I see a lot of mini sites that are miles long. The reader has to keep reading and reading to get all the content. Might as well be a full scale site. If it is kept simple and short with good content, a 1 to 3 page mini site can be very successful. If the content is good enough, you won't have to pack your site with tons of info to get the point across.
Good luck.
Dennis
Mini Site Templates and quality products with resell rights