Yes, they are especially if the blogs have high PR. It would be great if you have hundreds blogs where you can post your article. If you don't have such blogs you can sign up a membership of SENuke, SEOLinkVine or UAW
If you are using a blog, install the free automatic backlink generator from bloggerhigh.com You'll get drip fed several thousand 1 way links over the year, no action required.
effectivity of a back link on a post depends upon the content of that post. the more rich and attracted the content of the post will be, maximum no of users will access that link
They are very useful, the only things which you should always remember that the links should be relevant and do-follow, also the blog should have a high PR. I have used this facility and have been very benefited, they instantly boost your rank.
In fact, writing guest posts with backlinks to your page will have a positive effect for you. But don´t focus too much on PR, because articles in blogs normally don´t have PR above 1 or 2, except of very good and unique content. That´s actually what you need to focus on, good and unique content. If you don´t have the time to write these articles by yourself, you good ask the blog owner if he likes to write it by himself and if he is willing to give you a backlink by this way. There are also some professional market places (text link ads for USA, teliad for Germany i.e.) where you have the possibility to find these kind of link-partnerships...
it creates hirarchy links to your websites once that page is fetches by google.so its good activity also you are geting backlinks also.
Yeah, that is indeed backlink for site. But make sure two things 1. blog must on high PR. 2. this blog must be do follow. Thanks
Sure, they affect much if the blog is do follow and has good PR. The main profit of a blog link is that they send a true user. And normally the user becomes your customer
Link building in blogs is effective when you know how to do it. It is best to post blogs on DoFollow links and blogs with high page rank. Make sure that your posts are relevant, and related to your niche. This will be effective in making your target market follow your link.