This was only going to help promote gmail. Now instead people will be trading them on the blackmarket or ignoring the rule or dropping the service all together. While it may go back to the intended usage Google was stupid not to realize that all this was going to happen or either this is the next step in a calculated plan. Last thing Google needs is to be known as the big bully.
The part you highlight is also very clear to me. They changed their policy to stop the selling of ACCOUNTS, not invites. I thought this important enough to repost.
Any mention of banning the sale of invites is pure speculation by the article writer. And there have been quite a lot of misinformation spread by reporters as they all write their first articles on Gmail, and Google staff won't comment due to the quiet period prior to the IPO.
Buying and selling gmail invites is a great promotional tool for google.
It only hurts them in the end.
"The changes are designed to deter people from creating multiple e-mail accounts with the purpose of reselling or trading them, according to a source at the company. The policy alterations do not target people trying to barter Gmail invitations, which allow people to sign up for a new membership."
For you to make some money on selling the email invites is wrong but to barter (give them away without the exchange of money" is fine.
a funny aside. Looking at the ebay items for sale when searching with just "gmail", there used to be only a couple of accounts for sale in the 2500 or so total invites for sale. Now, on some pages of 50 items, there are just as many firstname.lastname@example.org for sale as there are invites. Definitely was not like this before the announcement.
So, these sellers either:
1. Are trying to sell the accounts they regged months ago before Gmail/ebay enforces the NEW policy, OR
2. Saw the announcement, thought "why didn't I think of that", and are now regging and selling the accounts as quick as they can?