Don't do it regularly, because people get PO'd, and you won't be the last person to lose a follower due to this. I've stopped following around 3-4 people because they can't keep other people's or their own Hubs away from my feed. If there's an article that applies to me, then I'll accept it. But I'd really appreciate it if it wasn't full of 5-minute reads and useless information.
Sharing Hubs is good, but be sure to return the favour for other Hubbers - keep their feed clean, and help them out when they need to spread the word.