Bottom line, those reviewers who said this device works for watching video on their TV using their computer are correct. Those reviewers who said it didn't work are most likely wrong, reason being they didn't know how to get it to work.
I needed this device so I could use my old Insignia 27 inch tube TV as a second monitor for my netbook. My TV has 2 RCA inputs(red, white, yellow), one in the front and one in the back. It also has S-video in the back and a composite input in the back (green, blue, purple). This device came with 4 cords, an S-video cord, a VGA cord, an RCA video cord(for the yellow RCA input), and a power cord that goes from the device to your computer by plugging into a USB port on your computer, You can buy an adapter for cheap that will allow you to plug the USB power cord into a regular electric outlet which I would recommend. My computer plugs into the device using a VGA cord and my TV can plug into the device using either the S-video cord or the RCA video (yellow input). I found that I could get better definition using the S-video cord but the RCA cord (yellow input) gives a lighter picture so you may find you like it better.
My RCA input on the front is Input #1. The S-video and RCA unput in the back both share Input #2 (which means you can't have two devices plugged into both the S-video and RCA video in the back of the TV, So I have my DVD player plugged into the RCA input in the front, The composite input (green, blue, purple) is listed as composite on the TV, So channel 3 is my Dish, Input 1 on the front of my TV is my DVD player, and Input 2 is my computer through this device using the S-video on the back of the TV, I don't have anything plugged into the composite input on the back of the TV,
Now that you know how to plug everything in you need to know how to adjust the device so that it works properly. The instructions that come with this device are not going to help you at all trust me, you're going to have to figure this device out yourself but I'll help as much as I can. First thing you need to do is make sure your computer monitor is setup to project onto a 2nd screen by right clicking on your desktop and going to properties, settings tab, and clicking on the #2 monitor and clicking the box that says Extend my Windows desktop onto this monitor. When I first turned my TV to Input 2 it was just wavy lines moving very quickly from top to bottom, it was so bad that when I pushed the menu button on the device I couldn't even read the menu options. Luckily the manual was useful in this one respect as it has a picture of what the menu looks like. So using the picture as a guide I scrolled down the menu options by hitting the down button on the device 7 times and then pressing the left button on the device until the picture stopped with all the crazy lines and looked normal...mostly normal anyway. The setting is NTSC but the device comes with the default setting of PAL BDGHI. Now that you can actually read the menu you can scroll down further to where it says CRT and change it to LCD. I get better definition on my TV with the LCD setting but you can play with yours and see which you like better. After that I just adjusted the picture settings to get it to fit my TV and get the definition and color as good as possible. Also, the directional buttons work when the menu isn't being used. If you just push the directional buttons on the device without pressing the menu button first it will move the image on your TV in the direction you are pushing. This is useful if your picture is the right size but not centered on your TV.
Other things you can try doing to get the picture quality better is experimenting with your computer monitor settings like resolution, refresh rate, etc. You can also adjust your TV picture settings but of course when you watch regular TV you'll have to either change your TV settings back or just live with your TV looking a little different than it did before. Personally I did fiddle with my TV settings but decided the improvement if any that I got wasn't worth changing my TV settings for when I watch stuff on my dish.
Lastly, like many reviewers have already pointed out, this device does not work for sound. My solution to this was to get a cord that is RCA (red and white) on one side and headphone jack on the other. I plugged the RCA (red and white) into the back RCA input of my TV and the other end of the cord plugs into the head phone jack of my netbook. Further, I used a second cord (RCA red and white one end headphone jack on the other) and plugged the RCA (red and white) end into the back of my stereo and the other end into the headphone jack on the front of my TV. So my sound goes from my computer to my TV and from my TV to my stereo.
And that's how I watch TV and movies on the internet using a 40 year old stereo, a 15 year old TV, and a 7 year old netbook.