This post was actually my reply to an email, but I felt it cleared up a few things that weren't completely clear.  It's sort of anti-SEO.

First the question:-

"Ok, if I uploaded a zip file I want to sell, and use SmartDD, wouldn't that file, that is on my server, be indexed anyway?

I mean the buyer wants to know the location but the search engine looks at the entire site, or do zip files not get indexed by search engines?  I read you can search for a pdf file."

And my response… 

Files only get indexed if someone tells the search engines where they are.  So for instance if you had a file called abc.zip and you put it in the root of your web site (and there was an index.html file there), nobody would ever know it was there except for you.

However, if you then put a link to that file on a web page, you've now increased the risk of it being indexed.  But again, if you don't tell anybody about that web page, you're still safe.

The moment you create a link to that page from another page is when your problems begin.  Even though it may be a page that only a paid customer could get to see, they may use http://del.icio.us to bookmark it.  That happens a lot.

When it gets publicly bookmarked, then it gets indexed by the search engines.  If someone posts the link to that page on a forum, again the search engines will sooner or later index it.

As long as a file is created and sits on its own with no links to it, it will never get indexed, and so it's effectively invisible.  The same is true of any file including PDFs, but excluding index.html, index.htm or any other kind of index file.

SmartDD works to secure files in one of two (or both) ways.  If your hosting allows it, you can store the files outside or above the web root.  cPanel hosting such as provided by Hostgator lets you do that.

When a customer buys she then gets access to the purchased file provided through a special download page and special link which streams the file to her PC.  There's no way the file can be accessed directly by a browser as it's outside the web root and she can't physically navigate to it.  Because she can't navigate to it with a web browser, it can't be indexed by the search engines.

Also, the link itself can be set to allow only a certain amount of downloads to that customer, e.g. 3, and it then expires.

The special download page presented by SmartDD works to dissuade people from sharing it by displaying their full name and email address.  That's not really something anybody is going to do, even for a friend, as friends can sometime share things with other friends, and they share with other friends…

The second way that you can use SmartDD to secure your files is by using the "Display Name" feature.

If you have a host that doesn't allow you to place files outside the web root, then you can set SmartDD to deliver a file using a different name.  So for example, if you have a file called abc.zip, you can deliver it to your customer as xyz.zip.

Again, that would be impossible to index if there were no public links to the directory.  With SmartDD, the customer never gets to see the actual directory that the file is located as the files are streamed to your customers PC through special code.

So by using one or the other method above (or both), and in conjunction with the streaming delivery method, plus the "social engineering" of placing your customers name and email address on the download page, you can completely secure any file.

Here's how you can improve your eBay income really easily, this is *so* simple to do.

eBay allow you to place links to third party services or tools that you use to assist you within your listings.  Just take a look at a random set of listings on eBay - you may even have some some of these links on your listings already:-

Auctiva.com, Vendio.com, Turbo Lister (yeah I know that's eBay's own), Spoonfeeder.com and so on.

Some of them automatically embed links back to their sites, you don't have any choice in the matter.

And NONE OF THEM are running affiliate schemes - you make NOTHING by having those links there.

That's not very fair is it?  You're advertising for them, and receiving nothing in return.

The eBay policy on third party acknowledgements can be found here:-

http://pages.ebay.com/help/policies/listing-links-credits.html

Here's a snippet.

"eBay allows discrete identification or credit for third parties that provide services or products directly connected with the particular listing as long as they meet specific requirements…"

So why not put YOUR affiliate link back to SmartDD.com in EVERY LISTING, and make 50% of the sale price in commission payments? 

It's okay, eBay allow it.

To you (as the listing submitter), SmartDD is a third party tool just like the ones I mentioned above, and you're using it in your listing to provide delivery.

So take advantage of it right now.

This is how to get your personal pre-made affiliate link to SmartDD - it will take you 60 seconds of your time to get it.

1. Login to the www.SmartDD.com site using your email address and password you registered with.
2. Click on the Promo Tools link.
3. Scroll down to "Step#5 - Banners And Images".
4. Copy the code in the box for "eBay Image Number 1" - your affiliate link is *automatically* embedded in the code for you, you don't need to change anything.
5. Paste the code into all your eBay listings.

Now when any buyer sees your listing, they'll also see your affiliate link to the SmartDD.com site.

You'll get 50% of the current sale price of SmartDD for every person that buys through your link.

The reason I gave you the stats at the top is because SmartDD is something that ebook sellers genuinely want.  All you have to do is let people know about it with your affiliate link.

And here's what I've noticed.

When I've checked my web server logs, many of the new members to the site are coming as a direct result of people clicking affiliate links *within emails*.

Relatively few are coming as a result of people clicking links on *web pages*.

You already know that when SmartDD sends out an email for you with a download link inside it, it will automatically embed your affiliate link within the email. 

But by spending a few minutes with your listings, you dramatically improve your chances of income from even a 99c listing.

Think about it.  People are going to leave your listing one way or another, why not put a link they can leave on that can bring you in some extra cash?