I anticipate Google to swallow Review Services market using G+. I hate the idea of somebody having total control on everything, but when I buy a product (any product), I see number of variations from different producers. I want to read some reviews, to see some ratings on products and their producers before picking one. That’s natural. Where to get those? On the site of producer/seller? Oh, please! I would rather not trust them entirely. Well, I could try to search on www.consumersearch.com or try www.epinions.com, though I would hardly find many of the products sold in Germany and the reviews by the locals. I’ll tell you what, I’m going to end up extracting reviews on public forums and likely giving up after hours spent in vain. However, I can use Google Products (www.google.com/products) and find everything in the place. I may even make a photo of the product right on the shelf of the store and try googling by the picture.
But in real life it’s not all so nice. Let’s take a watch - Fossil CH2746. Google Products has the item but no reviews, no rates, only seller ratings. The problem is you cannot rate or review the item directly from the spot you found it, but only going to Google Products page, what is you unlikely do. That’s slightly better with places (places.google.com). You spot one by Google Map or by checking in on one of Google services (Latitude/Places/Plus) and get on the page with reviews. Moreover, you have references on 3rd party review services (e.g. here in Germany www.prinz.de, www.qype.de and www.yelp.de). That all because you find the object on the same repository, as used by review and rating services. It is not going to work with consumer products. Thanks God, nobody can monopolize the entire Internet. Thus, the fitting place for products is on the pages of numberless sites. What I expect of Google is applying the aggregating tools they have already to populate their review/rating data bases.
Look over there, ‘big brother’ has already revealed +1 button, so to say, global rating tool. It brings people rates from millions of sites to Google. The only problem here, you can rate yet only an URI. So if I rate iPad 2 on overstock.com, I actually give points not to the product, but to overstock’s page. Google was one of early evangelists of micro-formats. Hproduct (http://microformats.org/wiki/hproduct), the one to describe a product on a page, contains identifier field supporting at least 10 product unique number types. I expect Google to tie +1 button to the product identifier. For instance, when +1 works with URIs, they just can have product pages of the URIs based on the product numbers (google.com/product/isbn/xxxx). Google bot extracts iProduct meta-data all the time anyway. The only change is how to use it. Not a big deal for Google, er?
As for the reviews, when +1 JS-code attaches the button on the product description, another JS may attach the Share button. It’s like you found a watch on the Fossil site and you can rate the watch (the product) by +1 or share you experience/opinion with your friends on G+. A checkbox “Would you like make a product review by this post?” would be ok to warn user.