That being said, all three have somewhat managed to co-exist with one another peacefully, at least until a recent change that Yahoo will be making in which future access to Yahoo’s products/services will require you to sign in with a Yahoo account. This is compared to before where one could sign in using a Facebook or Google account.
This was confirmed by a Yahoo rep to The Verge where they said, “This new process, which now asks users to sign in with a Yahoo username, will allow us to offer the best personalized experience to everyone.”
This will kick off with the “Yahoo Sports Tourney Pick ‘Em” which is a fantasy college basketball service and will eventually move on to other services of Yahoo, eventually phasing out all access by Facebook and Google accounts.
We’re not sure why Yahoo would want to limit access, since we’re sure that they will definitely lose some users in the process who might not want a Yahoo account, but perhaps they’re creating a sense of exclusivity and maybe even a community of sorts.
Either way if you use a lot of Yahoo’s products and services and you still sign in using a Facebook or Google account, perhaps it might be a good way to sign up for your own Yahoo account now lest you run into any issues down the line.