What do we mean by a 'Interactive Site'.
You may need an interactive site in some situations. Typically an interactive site is not needed by a small business.
If you want to collect feedback from your visitors then you might want a feed back page. Typically this is written with a server side script such as ASP, PHP or Perl. The visitor fills out a form and then the information is emailed to you.
If you want a guestbook on your site then you would need an interactive page. Again this would consist of a form the visitor would fill out. The information would be handled by a script written in ASP, PHP or Perl. The information would then be collected in a database such as Access or MySQL. Then there would be a View Guest Book page that would show all of the entries.
If you want a page that provides a quote or estimate for the visitor you would need an interactive page. A database would hold your pricing and product/ services information. The visitor would fill in a form. The form information would be handled by a script written in ASP, PHP or Perl. The script would then combine this information with your Pricing Database and then present the quote to the visitor.
If you want to sell products on line you would need an interactive page. Your database in this case would be quite complex. It would contain information about products, prices, current inventory, customer information, customer address, customer billlling information and more. The visitor would fill in a form to buy the product. Then the various scripts would collect the billing and customer information. Finally you would receive the order via email or with a file sent to your ordering system. These systems better known as ecommerce are quite complex and expensive to build.
For most small businesses I would advise against any of these features.
A feed back form might generate some inquiries from your friends and customers. But unfortunately what you will mostly receive is unsolicited email. I have seen several sites that have disabled their feed back pages for this reason.
A guest book will also get a few comments from friends and customers. But unfortunately what you will mostly get is unwanted postings. A local web site owned by a very reputable individual has this issue. His guest book has become a chat room for rather seemly characters and purveyors of obnoxious products.
A quote page could be useful so that customers get a sense of your pricing. A safer option would be to simply create a page that lists your prices. Welcome them to email or call you for further information. Another option is to create a JavaScript page. This would not capture their request but it could give them an idea of your pricing with various options.
An ecommerce page, or shopping cart, or catalogue page is quite necessary for some businesses. In this case I would advise outsourcing the work on this. There are existing shopping cart systems. Some sites are created by credit card processing companies. Some are created by large internet auction sites. Some are created by shopping cart companies. You simply sign up with one of these companies. Then give them your credit card or bank information. Then provide a list of your products with photos if available. On your own site simply create a page with links to this other site. Then this ecommerce site handles all the complex issues around security, databases, credit card processing, etc. They may charge a set up fee and also a percentage of what you sell. The 5 percent it will cost you is worth it. If you are only selling $20,000 this might amount to $1,000. Meanwhile creating your own ecommerce site might cost $10,000. Then again if your sales grow to $500,000 then the $25,000 you are paying out will be too much. At that point contact someone to set up an ecommerce site for you.