I used to own the giant vine channels (Buzzvines, Bestvines, etc.) on youtube before selling them. I know most people say go ahead! Its never too late. But honestly, for vines, I wouldn't get into them unless you have some cash to invest and grow your accounts on IG. At the same time I started my yt channels I did FB too. The thing is, I got millions of views within weeks on YT, while all in all on facebook my page got 25,000 likes. Why? (Sure maybe my advertising of the page sucked and it could've been better, butttt..) It wouldn't have reached the same success as my channels. Simply because there were like 20 big facebook pages already while on youtube I was one of the first. For instagram, I mean, theres giant vine pages right now and it's really a small niche. It's pretty specific, since mostly for vines you'll only have people wanting to watch either comedy vines, action vines, celeb, or something cringe/weird.
Anyways, let's skip over all of that. I'm not telling you don't do it, but if you want to, you must realize you will never get the followers as fast as they did and you'll require much persistence. Those vine pages got their millions in a relatively short time, probably when vines were the big thing. Now they're growing just because they're so massive. Sure you can reach a million followers, but like someone else pointed out, it'll take years. Best thing to do? Look for something else that's viral right now. Heck, even the charlie charlie posts on IG when they were popular for like a day last week got a few accounts decent followers. I saw a new account get like 20-30k just because it went slightly viral. There's tons of small things like that every week on IG. Good luck with whatever you do. And also, I tried paying for shoutouts in the past but it doesn't get you much followers. It works.. yes, but it's overpriced by about 10x-15x.