Thought it worth adding to some discussion here on this for you Ric.
Posted this comment on the blog:
Can see both sides of the coin here Ric.
However, in practice (admittedly on the few fairly high traffic sites I've got where there's a strong social networking factor) I've been finding that by having visitors able to follow/like/etc that overall traffic is lifted...
This is by having an overall social networking strategy that means that followers/likers will be notified about new content in some way that is more likely to drive them back to the site sooner than having them come back just on their own volition. News article posted to facebook and twitter on one site in particular result in a 2000% traffic spike in the 12 hours following the item being posted as the few thousand followers all see the item and click through from the social networking site they initially subscribed to from the link on the home page of the website.
I do note however that I do aim to keep external links from home pages to the bare minimum - with social networks being usually about it, unless there's some other specific need to do so.
Personally, widgets for facebook and twitter are possibly more what you're talking about rather than just giving the user the ability to follow? The widgets can only really provide value adding if the content from the streams is not elsewhere on the site. In the example I've mentioned above, the site's RSS is what is going out to facebook and twitter, so displaying the feeds back on the site is fairly useless.
