Because long-tail keywords are so specific and geared toward a small group of searchers, you have a much much better chance of being the top-ranked website for those terms. Achieving the top rank for a keyword gives you a major advantage over your competitors. Most people click on the first site that comes up in search- and if that site is yours- then you have the best chance of making a searcher a customer. Another benefit of long-tail keywords is the specificity of the term, because it is so targeted the searcher was most likely looking for exactly what you offer. Take a clothing boutique for example. While the owners of the site might be tempted to only target keywords such as “dresses” or “designer jeans,” it will likely be difficult for their site to compete with large internet retailers for search visibility on those terms. On the other hand, if the owners of the boutique target long-tail keywords such as ” Zac Posen cocktail dress”  or ” Dark denim skinny leg jeans” then they are much more likely not only to rank highly but also to receive visits to their site from customers actually looking to purchase what they are offering. Long-tail keywords are much more likely to convert into a sale than short-tail due to the specific nature of the term. 

Since you will be targeting such detailed terms, you will have to create more pages to cover all the different variations. In general, search engines (read Google) are rather fond of websites with many pages due to the fact these websites are more likely to be reputable and knowledgeable. They give the search engine spiders plenty to read and rank, and search engines like that. It never hurts a website to employ methods that search engines respond well to and they respond very well to long-tail keywords.

In the end, it’s a matter or high search volumes without conversion/sales (short-tail keywords), or lower search volumes that translate into revenue (long-tail keywords). I’ll have the revenue, please.