Likes and Views: Link to video
Subscribers: Link to your channel in its full form
Short link: https://www.youtube.com/user/YouTube
To get full link: If YouTube is giving you the short version, go to any of your videos and click on the channel name. Now you should have the full link.
Likes and Views: 1000 views and 10 likes minimum per video
Subscribers: 50 minimum per channel
Likes and Views: Medium-fast
Subscribers: Slow (1000 would take about a week)
Likes and Views: Instant, though it takes a few hours for YouTube to start registering the views
Subscribers: Up to 12 hours
YouTube subscribers make your channel appear more popular. Additionally, in some cases they increase your visibility in search results. This makes it more likely for people to subscribe to you.
Likes and views will boost your video in search results. As long as your SEO is done well, your video has a much higher potential to rank better for the keywords you included.
Note that the subscribers likes and views added by this service are not actual people. They help you gain actual people.