The crawlers can read the comments but the url links are nofollow. Don't forget...main purpose of blog commenting is to add value to the blog and not for something like link building. Because of that it's not what you would construct as time wasting.
I think it is not wasting time, dofollow blog will provide you PR juice. Even the blog is nofollow, at least you can gain some traffic.
And yes it is good for link building, Google loves blog comments, but from what I've heard, you have to ping your blog frequently if you want G to know that there are changes noted. Google also loves Squidoo and Hubpages, and they are similar to blogs, you make your own pages and update them and you get comments there, and G uses those in their search results for keywords... James
They won't be crawled as blogspot use nofollow for the links is comment. Though it will increase your Yahoo backlink.
No i heard it is useful to comment on other sites. specailly in blogger and wordpress can make diff to PR also and other thing is by commenting can get more traffic that is the best thing i ever seen it is good to comment with url in every site and there is many advantages with commenting so acutally it is not time wasting.
sorry, i should have worded my question better. I know that google can of course READ the comments, but what I meant to ask was, are the links in blogger dofollow or nofollow. It appears that they are nofollow from what everyone is saying.
someone should also add, that make sure your links have substance, links for links sake might not even let your comments make it to light. it amazes me how many people submit comments to a blog with unrelated links without adding substance to the discussion
Blogspot blogs are the same as wordpress out of the box they are no follow but you can change that - my blogspot blog is do follow - and I will accept intelligent comments !