My concern with the long sales letter approach is how relevant it is to web apps. Mail order books, courses I can see the benefit, but with a web app, why write lots of spiel about a product someone can start using straight away with a trial account. I am at constant battle with my business partner over this as personally I don't believe it is the right way to create a conversion with web apps (How many successful webapps can you name that take the long sales letter approach?), where as he takes a more traditional info-marketing approach based around selling courses/books/seminars and wants to apply those techniques to our startup.
How does a long sales letter form compare to an approach of "Get the user using the product as quickly as possible", with a few bold benefits outlined, a huge "Try Now" button and not commitment to buy. Of course this is something that I should A/B test myself to really find the answer.
Even with a free trial, the purpose of a long sales form is to explain why APPNAME.LY is superior to all the other competing products and get you to try it out.
Look at Basecamp (http://basecamphq.com/). They have a tremendously successful webapp, and their landing page is long enough to clearly explain the benefits and uses many of the features commonly found in direct mail/mail order advertising.
The thing is they have professional graphics, high profile clients, high quality video testimonials & upfront pricing. The website is actually pretty free of gimmickry. While it is long the actual text is only about 3 paragraphs. Also you're on their homepage, which is more trustworthy than your e-mail inbox.
There's a pretty big difference from Basecamp's website vs someone trying to get you to buy "Forbidden neck pain reliever that the pharmaceutical companies don't want you to know about!!" or a cheap saw made in china that will probably break after a month and cost too much to send back for the Money Back Guarantee*.
What you need to do is display all the benefits your product offers, show how YOUR web apps are different, exploit your USP and tell the world about it... and debunk all objections.
That could take 500 words... it could take 2,000 words... or it could take 10,000 words.
It all depends. Long copy isn't long because people "want" it to be long. It's long because it takes that long to tell people how awesome the product is, as well as get in touch with them emotionally.
Well in many cases the actual cost of the product was covered in the "Shipping & Processing Fee". To return the product the customer would have to pay the shipping back as well. Sometimes they say they'll pay shipping back, but they've probably accounted for this by making a higher initial shipping cost or making a it a pain in the butt to return or just by conveniently "going out of business" after a month or two.
How does a long sales letter form compare to an approach of "Get the user using the product as quickly as possible", with a few bold benefits outlined, a huge "Try Now" button and not commitment to buy. Of course this is something that I should A/B test myself to really find the answer.