OK - re-read my comment with the word 'unsolicited' removed.

It is still unreasonable to send out legal threats because you did not receive a response from an email. You don't know if the email was read, or if it was even delivered to the user's inbox (it could have been flagged as spam, for instance). Or, as it appears to be in this case, it could have a poorly worded and misleading subject, causing it to be ignored.

Furthermore, did you read the email that was actually ignored? It is linked in the article, and located here: https://gist.github.com/1833289

Note that it specifically says that "if you agree to this arrangement" to implement the link back. There is actually nothing in that email that would suggest that any action was required; the next step sans link back was simply for Gigya to then send a price quote.

While I am not suggesting that the alternatives offered are or are not fair or reasonable, the follow up email did its job in getting the service consumer's attention and more importantly action in regards to the matter.

Well, naturally. I was not arguing that being unreasonable was not effective in forcing action on someone's part. I would argue, however, that it is unethical and counterproductive.

>"It is still unreasonable to send out legal threats because you did not receive a response from an email."

Hardly unreasonable universally - particularly when it comes to non-payment.

And it is clear from the first email that the link back is an alternative to a license fee [from your link]:

  Hello,

  My name is Atara Herskovics, Senior Marketing Manager at
  Gigya. We're pleased that Muziboo.com has been enjoying
  Gigya's Wildfire share plugin for a while; 
  however please note that as part of Gigya's
  business model, for the last couple of years 
  we have been charging a license fee for the use
  of our social plugins. In recognition of the
  fact that you were one of Gigya’s first clients, 
  we would like to provide you with an alternative
  option in the form of a link to Gigya
  that you would place on your homepage.
  If you agree to this arrangement, please 
  implement the exact link below:
  <a href="http://www.gigya.com/">Social Media for business<a/>

  Alternatively, we can send you a price quote for your   
  continued usage of our Wildfire product.

  Thank you,

  xxxx yyyyyy
  Senior Marketing Manager, Gigya

Email deliverability isn't a guaranteed thing though. Usually that's fine, but if the argument is we're going to charge you because you didn't take action, wouldn't you need to prove it was either sent or received? Maybe I'm just really old school, but I'd think registered mail or something would be required in that case.

IANAL, but when I served on a jury most (if not all) of the emails relating to the case were not admissible as evidence because there was no way to prove authenticity, delivery, etc.

>"wouldn't you need to prove it was either sent or received?"

[IANAL] Probably not (in the US). In the US, anyone can sue anyone else over anything. [Not that I doubt email notification might present problems in court - but who is going to court over $6000?]

Legally what you are saying could be right. But what if even this email was ignored as an unsolicited email?

Is it right thing to sue them because they have sent 2 emails for a service that was offered free? Definitely not.

The right thing to do would be to terminate the service for such a free user & get their attention.

It would seem to me that if the service was free, no money exchanged hands, therefore no contract exists that would make any sense in court. The only recourse they would have is to shut off access..... they'd have nothing to sue over.

Contracts do not live or die on the basis of whether money changed hands.