Alert user's friends in social networks?

Question

API

To better explain the situation, I will try to do this with an example. There is a certain service on the domain.ru domain, on which the user, in most cases, logs in only through the social networks API or an OpenID identifier, after which he creates events, while indicating the friends who should be notified about them and the notification method.
Everything is clear about sending messages via SMS and E-mail, but how to notify our user's friends so that they are guaranteed to know about the event through social networks. networks?
I know apps (on Vkontakte) can send notifications, but there's too much garbage and most people just won't read them; there is no point in throwing an invitation on the wall - it is personal; No one will give you access to private messages. You should also take into account the fact that such a message is sent more than one and calling frames for each sending will kill the whole idea of ​​​​automation (the question of protection against spammers immediately arises).
What ideas? And how are things with Facebook and Twitter in this regard?

Answer 1

I think you just need to cling to the walls - either in FB or in VK. I don't think it will be too personal.