If anyone would like to discuss further, then Iinvite you to contact us directly and we will be happy to have a full lengthconversation about it. 

It is very important to me that misinformationis not floating around here to confuse store owners. 

1)  As wealready posted above the W3C issues will likely be resolved in the nextrelease.   We have been… and still are…working on W3C compliance, but it is a process. So to be clear, we are working on W3C compliance and many pages alreadyare compliant (or extremely close). 

2)  Youmention Google "may" validate HTML in the future.  If they do ProductCart will be ready!  We have always stayed on top of the latestSEO requirements.  It is not correct (andvery misleading) to suggest that W3C compliance will affect rankings.  We can have an entire conversation on thoseservices and tools you mention separately, but it is a fact that Google doesnot validate your HTML today.  It is veryimportant to be clear on this point as many store owners are compelled bymisinformation to spend time on things that have little to no impact on theirrankings. 

3)  Ourposition was not based on an article found on the web.  Our team has extensive experience with SEOoptimization and subscribes to all of Google's blogs and feeds.  We watch of all of Matt Cutt's videos and useyears of real world experience in drawing our conclusions. 

4)  Greg,as a long-time reseller, your customers are store owners.  As you are saying, store owners do care aboutW3C compliance, and that is exactly why we have said we are working towardsit.  What I said is customers are notchecking for it… and by customers I mean "shoppers".  How many shoppers to do you feel run yoursite through a W3C validator before they purchase?  We have spent the past year focusing ourdevelopment on the top features that will increase SEO ranking and sales “forreal”.  For instance, our work withGoogle Trusted Stores is a much better indicator to a customer that your storeis trust worthy than if your source code contains an "aligntag".  

Our goal is the deliver the best possiblesoftware and we've spent our time on what we feel is the most valuable in termsof cross device compatibility, generating sales, and effective SEO.  W3C compliance will come, but if you arelooking at reasons to upgrade there are dozens of new features with concrete value over W3C.

I'm no SEO expert, by a long shot, so I don't want to debate the merit of W3C compliance as it relates to SEO.  But I do know that when our merchants engage SEO consultants, one of the very frequent requests that happen early in the relationship is that we are asked to perform a W3C cleanup.

When our customers start looking at SEOMOZ, Webmaster Tools and other sources that complain about various code issues – they are inspired to respond (or ask us to respond) to the laundry list of changes that those tools recommend.  If there are issues that can be resolved, such as W3C compliance, why leave them up to discovery by such tools, and thus open to debate by web site owners? 

I see the article from which you likely drew your assertion that "most SEO experts agree", along with the video of Matt Cutts. But here is more from Cutts.  From this article:
http://www.contentcustoms.com/blog/does-google-penalize-for-invalid-html/
<<<Cutts says there’s no guarantee that they won’t somehow use HTML quality as a ranking factor in the future, but for now, your primary concern when it comes to ranking should be providing relevant, truthful information to your users in a way that’s easy to navigate and understand.>>>  Just the fact that it might matter to Google in the future, or that it might matter to other search engines, leaves me believing that W3C compliance is fundamentally important.

With regard to your assertion that "At the end of the day Google and your customers are not going to be checking W3C", that may be true of the merchant's customers, and it might even be true (subject to future changes) about Google.  But I entirely dispute that point when it comes to me as a developer dealing with my clients who run these stores.  THEY WANT W3C COMPLIANCE - I know that for a fact.  Brett's thread here is a perfect example.  We deal with these requests, for whatever reason, all the time. 

Most SEO experts may indeed agree (at least according to that article which we both read), but there are enough SEO consultants out there that will be telling clients about the importance of W3C compliance, that I don’t expect to stop hearing about it just because you or that article take the position that W3C compliance is not critical to SEO.  Many web site owners believe that to not be true, or are told to believe it to not be true, and for them it becomes gospel.

Additionally, it was made rather clear in the lead-up to releasing v5 that W3C compliance was a planned goal of this new release.  Did something change and you guys decided to take a pass on that goal?

Hi Brett,

Most SEO experts agree that W3C validation has no effect on SEO rankings.

Don't take my word for it.  

Matt Cutts of Google says in the video below that Google does NOT check W3C validation.

https://www.youtube.com/watch?v=FPBACTS-tyg

Google's own sites have hundreds of W3C validation errors.

ProductCart v5 follows SEO Best Practices and includes several new features to help your rankings, such as including microdata.

This is by far the best version of ProductCart ever released.

There are dozens of new features to help increase sales that your customers will notice.

At the end of the day Google and your customers are not going to be checking W3C.