How often are the social signals of a domain updated?
The crawler that updates the social signals that we display inside the Toolbox operates with a variable and self-learning update frequency. The above makes it so that URLs whose social signals numbers change frequently are updated hourly, while other URLs – which had no or only slight changes happen to them in the past – are only updated monthly. Therefore, all URLs are updated once per month at the very least.
By the way: If the domain in question is placed on the Watchlist, we often find more social signals for a domain.