News in the world of social media buttons this week:  Twitter debuted a Follow button for third-party sites. It is the equivalent of the Facebook Like button. The new Follow button lets Twitter users instantly follow a Twitter account without having to leave the site they’re on. Here are the instructions from Twitter on how to add a Follow button to your site. It is easy to install.Also, Google has recast its +1 Share button. Pay attention to this one, it can affect your search engine rankings! If more people +1 your content, it will figure into Google’s search algorithm. This development is experimental at the moment as Google search users need to opt in to use it. Here are instructions for adding Google +1 to your site.Tip: Find out which social media sites are the most popular among your users and concentrate on having those buttons on your site first. But you might be surprised by what you find out. Don’t assume a B2B audience would never share something on Facebook, for example.Yes, you can — and should — add social media buttons to the areas of your site that only paying subscribers can view. It’s a great referral tool.Just make sure that when they refer their friends or Twitter followers to the link, that non-members will automatically hit a paywall page that includes a headline and possibly a summary of that particular content. No generic paywalls!However, you should not add social media buttons to critical conversion pages such as paywall pages unless you *very* carefully A/B test them first. Anything that distracts from the conversion link can depress your results.