They are using nofollow tags in tweets..Earlier , the URL link in the profile home page was dofollow ,turned dofollow few months back . Worth if you have lot of followers ..
Twitter links nofollow but if you have a 'decent brand' or following, you might get decent traffic your way !
I remember before...on Twitter's profile page you can add your site and it has a dofollow attribute...but after a lot of people found out about it...the admin changed it to nofollow. I just hope they will bring it back..^^
Bookmarking sites are uses to index a website and to promote it at the same time. There are some few bookmarking websites that gives "backlinks", but mostly, it just drive TRAFFICS to the website.
The links from there are not really effective in terms of SEO but they surely can bring in a lot of traffic.
You get a little bit of link benefit. Twitter has a Mobile version of your tweets My Tweets This gives dofollow links. I've found this helps in getting sites indexed quickly You can find a bit more about twitter info at Twitter SEO
Twitter seems pretty useless to me. Getting a large following is incredibly difficult and time consuming. And even when you have a high following, there's no guarantee of much traffic (unless over 1000s) which is pretty hard to get anyway. Also, twitter is filled with spammers, non-caring people, and they are only interested in following someone famous/CEO/person-who-they-think-can-make-them-as-good. I wrote bunches of updates that are really interesting or entertaining, and no one even cares, not even your own followers. I even have an amazing layout and great topics, and then there are those people who talk about the most absurd bullcrap that's worthless, and they get tons of more followers. In other words, Twitter doesn't make your site famous. Your famous site makes you famous on twitter.
Twitter changed the bio link to nofollow a few months back (so no link juice flowing there) - and for me personally the traffic from twitter is not worth the effort. I might offend people here , but even if you do get a few followers, they seem to be apathetic (and no - that doesnt mean theyre pathetic - although at times one might think that!! ). Twitter doesnt seem to drive traffic like some of the other social platforms in my opinion
i find it not so bad for driving traffic. I have two twitter accounts targtted to teh two main niches I blog in and it drives about 10% of my followers per link to my site Not great, but it is certainly a plus, as well as providing a good bit of fun and social intereaction.
You don't need link juice from Twitter to be empowered by it. I get tons of traffic from my twitter followers and they are very active in my blog.
The trick is to try get your twitter followers targetted. most of mine come from my recruitment business blog or from various recruitment and business start up forums. These then are very interested in the sort of blog posts I write and so will follow the links I 'tweet' much more readily than you will if you just add as many thousand people as humaly possibly in the hope of getting follows yourself etc