Hi Senad:
I hesitate in answering since this is not a sales thread, but you asked, so I will reply.
I'm always careful/mindful when answering this question because I never wish to put down any competitor in order to show differences. I'd rather focus on the pluses that I offer in my product. But sometimes you end up crossing that vague line out of necessity to make your point.
Anyone can throw a basic tutorial together. Anyone can put in text captions that merely say "Click here" and "Enter password here". It's quite another thing to put together an effective instructional tutorial. Creating an effective tutorial involves proper storyboarding, research into the product itself and effective delivery to caption text. A good tutorial will often include extra relevant information or tips. For instance, when changing nameservers at a registrar, you can just say "Click here" to finish the process, or you can also add info about propagation taking 24-72 hours. In a cPanel tutorial about creating a MySQL database, you can just say "Click here", or you can also add info about how cPanel automatically prepends the database name and user with the account's username. When creating a tutorial in Plesk on how to add your logo to the header, you can just say "Click here" or you can also say that it should be in jpg or gif format, and that the ideal size is 558x50.
Well, you get the idea. Before I produce a series, I always go through all available docs to pick out valuable "extra" info that is then incorporated into the lesson. Telling someone to click here and there isn't really a lesson. Explaining to someone why they are clicking is.
Aside from that, take a look around at product on the market. Pay attention to spelling and grammar. Pay attention to timing of frames and mouse clicks. Pay attention to proper formatting of text boxes. Pay attention to consistent location (or lack thereof) of text boxes. Pay attention to overall continuity of product. All of the subtle (and not so subtle) points contribute to the overall quality of product, as well as effectiveness as a learning tool.
Aside from all fo that, consider the provider. Does the site offer just a few tutorial series, or can you select from a large inventory covering many different products? Will the provider be there in 6 months or 2 years when it's time to update the tutorials or buy more? What kind of customer service can you expect?
Anyways, there's more, but I won't bore you.
Vito