Thanks everyone for comments and also for criticism.
I think that EPN sites as Youtube related site are good if they provide something that helps the user, I explain.
If a beginner user goes to ebay it can be difficult even to find where the sunglasses category is, if then he wants to research for brand it's even worse.
I agree that a site with only ebay links is not useful but organizing it in categories, with logos etc. can be helpful.
Same for Video sites. Yesterday a friend of mine was searching the video of a gol from the soccer game Inter - Juventus on Youtube and he couldn't find it. I took the mouse and it takes about 5 seconds for me to find it.
If he could have gone to a site where there are only soccer videos, organized for team and match he would have seen the gol without my help.
Same applies for directories. What add dmoz.org to the web? It has no unique content...
P.s. I'm not saying that my site is fantastic or stuff like that, I manage some financial websites (in italian) that are 10 times better because are full of original content, it's only I don't think a site like this it's 100% useless.