I personally think annotations can get annoying, I've had people comment on mine saying "oh look, another person saying to subscribe" or "the video would be much better without the annoying popup links". I'll have to play with it, but I think I may go with putting the playlist link in the first line of my description. I just have to experiment with it to see how visible it is and how annoying it may get.
you put yours at the end??? The videos I've watched from your channel seem really long, that's pretty impressive to keep people's attention that long!
I rarely vocally ask people to rate or subscribe but I do have 'Subscribe' in my end-card. If I was a subscriber to a channel, I don't want to hear 'please subscribe, blah, blah, blah' every video!
I use 30-second annotations because I offer several options at the end of the video. I need to give them the time click. You could easily get by with 5 or 10 seconds if you're just using text annotations.
As Wreckless stated, the goal is to increase the watch time on your channel. I see that you have a lot of 1-minute videos. At the end of your video, YouTube puts up a bunch of recommendations for the viewer. You're going to let somebody else tempt away your viewers?
When you go out to a restaurant, don't they ask if you want dessert when you're finished? They have you in their house, they have to try to get you to stay a little longer and spend a little more money. When you have somebody in YOUR house (channel), you should be trying to get them to stay a little longer and watch another video.
I will share with you my strategy with end-cards. This track video is 16 minutes long! 39K views. About 20% of the viewers watched the whole video. That would be approximately 8K get to the end. Out of the 8K, 614 clicks. Now, 614 isn't a big number in relation to the original 39K views but that's over 600 people stuck around for an extra serving of dessert. Here's a screenshot for proof. The 4% I stated earlier was just off of the top of my head and is probably more representative of my 7-10 minute videos.
Now back to annotations, since the video that I'm talking about was a track
video, at the end, I show another track video. Plus, I give two links for
Track Playlists. If they want something different, I show a video for cars
and one playlist for cars (cases).
In your case, you could have these Playlists:
Dalmations
Dogs
GoPro
Military