[fabiandesimone]

I think you are mixing concepts.

First: new customers will forever know that the stated price is not the "real" price but a much lower amount I think the "real price you are referring to is the production cost, which generally (unless is subsidized) is lower than the sales price.

Second: if a service is normally priced at $50, and you now offer it at $25, your customers, even the ones who don't go for the deal, will now think the "true" price is closer to the lower price than the previous price

What is exactly the "true" price? As far as I know an item is worth whatever someone is willing to pay for it.

The only thing I can infer from your sentence is that a set of customers that won't even buy the product at discounted prices, have not yet obtained value from your product. Which can be in itself a great insight to work on the message of your product and hopefully be able to transmit value.

I think, that if anything, Groupon is a great way to flush out the low value customers from a CRM pyramid and focus on medium value customers and turning them into high value ones.