Just thought about it yesterday. I actually think this is an inevitable step for Steem to become a success story.

1. People want to be able to keep using the tools they are familiar with.
2. It would massively increase exposure to Steem.
3. Would make readers happy they can finally tip everyone they love without giving up anything :)
4. Would make blog posters post just for the sake of content - no need to integrate affiliate stuff into content.

Some slogan ideas for blog owners to get readers to join Steam.

"Join Steem Now and Tip/Vote your Favorite Posts Without Giving Up a Single Cent!"
"You Can Even Earn Money Yourself by Just Voting Valuable Posts :)"