Outros absolutely work, you just have to be creative about it. I think I have a fairly high view to subscribe ratio of 1 subscriber for every 35 views and I believe it has a lot to do with my outro. Here's the psychology behind mine:
A) Subscribe and Like
B) Share Me
C) Watch my Previous Video
D) "Tell me to Quit Youtube" (always different)
1. While I use the same format each time, I don't simply use the same video and I redo my outro each time.
2. Too many people make the mistake of asking their viewers to share, like, subscribe, comment, follow me on twitter and blah blah all at the same time. When people are bombarded with too many choices, they might not choose any. I use a multiple choice format so I'm only asking the viewer for one of 4 things. Now of course they can actually choose more than one if they really want.
3. Multiple choice kinda makes it like a game. Games are fun and people like choices
4. I use an IF statement. "If you liked this video... then choose one of the following." IF statements imply a value exchange. I'm not commanding people to like/subscribe and I'm not asking/begging people. I'm offering a trade of value.
5. I know option B) which I ask viewers to share is asking a lot. I put it there simply so the other options become an easier task. Restaurants know that very few people will order an Extra Large drink. But by putting that option in the menu, they know it will increase the sales for Mediums and Large. Why? Cuz people don't often like buying the most expensive item. Also I actually tell people, "B) listen to the share bear over there to show that you care." So it's not me asking people to share the video, it's the cute bear who is telling them to do so.
6. I change D) my last option for every single video, and I always make it something that makes fun of myself like, "D) Tell me to jump off the bridge / Hope my pants fall down." The Psychology behind here is that I'm not needy, it's not a big deal to me if you don't choose A), B) or C). In fact, I used this technique with really high success when asking women on a date through text back when I was single.
7. I keep D) a mystery until the very last 3 seconds of my video. This way subscribers who have seen all my other outros have a reason to stay till the very last second. This helps with maximizing watch time.
