Although it has not been officially released by Google, some businesses who use PPC have been seeing a change being implemented in AdWords which has increased the threshold of ratings for the seller rating ad extension to appear from 30 reviews to 150. All of the other factors for the seller rating ad extension to appear have not change including the following:

• The new 150 reviews have to have each been in the last 12 months.
• An average review of 3.5 stars out of 5 or higher is required to use the seller rating ad extension.

Why change the threshold Google?

Like with any change in PPC, there is usually a reason why it will be implemented and there are going to be consequences to the change too. Although the reasons for the change have not been confirmed (since the change itself has not been officially confirmed), we can presume some of the below reasons behind why Google increased the threshold of reviews for the seller rating extension to appear:

• To give the seller rating more representable – At 30 reviews, although that should give a good representation of the average review of the seller, it could still be fixed to some extent. All it requires is 5-10 people to review it five stars and the whole seller rating average will change. By changing this to 150 ratings, the seller rating will be a more trustworthy value and will harder to tinker to favour/not favour the seller.
• To give the seller rating more weight – At 30 reviews, it may not seem enough ratings for web users to trust the value given by the seller rating. By increasing this to 150 will give more weight for the web user to trust the seller rating.

What will this mean for PPC advertisers?

For those that already have over 150 ratings and use the seller rating, you shall see no difference in when and how the seller rating ad extension is used.
The biggest change will come for those that only have 30-150 ratings since this bracket of ratings will no longer be enough to reach the threshold of 150 ratings enabling the seller rating ad extension to appear on your PPC search advert. For the majority, this will affect small businesses which is a little unfair: it is not a level playing field anymore since larger businesses will, in theory, have more at their disposal in PPC when creating their search advert.
However, this should not mark the end of the seller rating for small businesses. The update to PPC has not been officially released yet by Google so there is time to spend some effort and money into enticing your customers to rate you more. That way, when the change does propagate, you will be ready with more ratings to enable the seller rating ad extension into your advert.
There are many ways you can entice web users into rating yourself. My favourite way is to offer a discount per customer rating of yourself as a seller. That way, you will get a seller rating, the customer will get a discount on their next purchase and you have also given the customer more reason to buy again from you as a returning customer.