I'm really surprised that many webmasters do not understand fully THE HUGE point here, really surprised.
The point IS NOT if search engines care W3C validation or if customers care W3C validation (they have probably no idea).
Maybe webmasters are too much focused in the job in the profession and into please customers… this is legit of course… but we all sometimes forget that at stake there is also internet and technology development to be considered for the future. We all care in the immediate in the short period of time of the small thing of the detail of the result but not of the WHOLE PICTURES.
W3C exist since years but regretfully few people see there the HUGE VALUE in W3C
Internet should be a better place for everyone starting from WEBSMASTERS that always complain about website with strange behaviors, about layout that do not look same in all browsers, about code soups done in the past (most in 90’) if there is the need of a restyling of an old website…. Plus one million bugs around.
Why we have to face all that?
It is because the marketing reason (not the tech reason) as the war between browsers have forced people to use the worst browser ever IE the winner was not the best tech but the best marketing, legit or not.
Netscape was far much better and more developed but lost.
Because of this only NOW after 10 years we are coming out to see finally in the market good browsers like Firefox or Opera and only now we see IE8 covering at least many bugs revealing the fact that they are far behind the line….
Only NOW after 10 years we all talk about the separation about markup and graphic about XHTML and CSS but this was already the main plan of W3C …. we all lost years of internet development due to stupid commercial wars and due to careless of webmasters.
I always make W3C complain website and I explain to my customer the add value of this. It not cost more nor do I spend more time writing a code instead of another. I also complained with big boys like Amazon (but there are many others) that offer widget to be copied in a webpage and their code is not valid, unless you change it. It is so hard follow the same line?
Beside I prefer to buy HP products because they support W3C.
I do hope that in future search engine will consider the W3C validation much more then the present link juice because without a common and clear code we all are loosing time and resources thinking to the code instead of contents and creativity.