I need to understand

It's very easy to get scammed buying on-line. I should know. It happened to me recently. I was buying an ebook. It was a guide for web developers to maximise their profits with the least effort. I was scammed though. The ebook turned out to be hundreds of pages shorter than advertised. I went to my broadband provider and asked them what I could do to fix this. They said there was nothing they could do, I would have to take it up with the seller. But the seller was in the Ukraine and we all know how lazy and useless the police in such countries are so there was no point appealing to them to arrest this man so I could get my money back. And even if they did prosecute him it would take years and the legal bills would be far worse than the money I'd lost on the ebook. So I decided if I was ever buying on-line again I would use reputable auction sites and marketplaces recommended to me by my broadband provider. They were very helpful and gave me a very long list of ones to go to. I went to them and was impressed immediately by the intuitive and user friendly layout. I ended up buying many high quality items from there. I went elsewhere on the information highway then to a forum and read many interesting discussions into the night. I eventually was broken out of my concentration by the doorbell the next morning. My stuff had arrived. It was great stuff. I would certainly be buying on-line again from the people my broadband provider had recommended. I then took my stuff and went on the information highway to the planet zog. I combined all the items I had purchased and made a giant laser cannon to do battle with the vile space Beatles there. They had taken over this once lovely planet and I felt it was my duty to take it back. But it was missing a magic crystal. I hadn't noticed that that hadn't arrived yet. so I had to put in a quartz crystal from my watch to set off the laser cannon. It worked. In fact it worked too well and the universe exploded. I managed to escape on the information highway back to earth though.