Microsites are not recommended because…
1. Your company will lose brand identity and audience engagement. Think about how much you have spent and will continue to spend through corporate energy and funds on positive brand perception and awareness. Building a microsite is starting over completely from scratch with an entirely new brand. If you are trying to reach an entirely different audience and your current brand would be confusing to this new audience, then building a subdomain would be a better option than building a new site or microsite. In most cases, microsites are subsets of or promotions for the main site, with exactly the same audience. There are two questions you should ask when considering a microsite.
Do you really want to work at building up multiple brand identities?
Do you really not want to benefit from the brand building in one category for another related category?
2. A microsite will confuse people and search engines. You do not want to exclude your regular visitors from your microsite content.
3. You can’t leverage all areas of your business. For example; If your company launches a new product andomeone writes up a positive article about this new product (with a separate microsite) in say, the NY Times, readers will start clicking over to the microsite. But, what if these visitors are also in the market for another one of your company’s products? If you have a separate microsite, you’ve just missed a great opportunity to reach a targeted and motivated audience currently looking for your other products.
4. A big part of rank is the number of inbound links from other sites. You don’t want to split partner links between two sites. You want to keep it all coming back to the main site.
5. If this is a new site and concept the buzz will not be as strong. Why not build up the buzz on your main site using the current PR and traffic as a spring board?
6. What about time and costs? You are going to have to spend extra time and money to maintain two separate places with different styles, and hopefully different content, etc. And…if you are building a microsite for a specific campaign, what happens when the campaign ends?Link to article