Anyone know if having non-visible links within an article or a paragraph are looked at any differently by search engines than those that are underlined or clearly marked. For example if in the above paragraph i had made the word "differently" into an actual link somewhere but the user could only tell that it was a link if the cursor was rolled over it - then it would change color or underline or something. On the other hand I could have just underlined it or given it a different color, then it would have clearly been a link but then there would be a greater chance of the user clicking away to that page then clicking on something else...like an ad.
I am pretty sure (99%) as long as the link is actually visible (not hidden with CSS, and not hidden by making it same color as background) it is fine. I haven't ever noticed a difference between having links underlined or not underlined, as far as SEO goes.
U can put link hidden there is not any problem with it, even internal linking is very useful to crawl all the pages rapidly. don't bother about it, i dont think that it will be harmful to your site.i have used that in many sites and all are doing well.
It is usual and common practice as well and will not be seen differently to have any negative effect. Yes from user visbility point of view, link not visible will surely not attract usres and thus traffic to that page. This is usually not advised for website playing heavy on "persuasion architecture" such as e-commerce sites or landing pages.
I agree, this is a very common practice. I've seen blogs that have links blended on their content. It's not entirely hidden or invisible, it's just camouflaged to make it hidden. Those blogs are doing okay with google. I believe this is safer than having your links blended or invisible to the background (Google, IMO, detects that)