How about reversing it? Help users search through various products, using what you know they like as a guide. Find deals for them. Instead of collecting data on users and using it for advertisers, make vendors give you tons of data and use it for your users.

I'm sure there is some good idea, just like becoming a prostitute is not the only way of making a living.

Perhaps it does not make much sense to make such websites if "advertising" is the only viable option?

Pintrest is mostly made up of (1) images/photos and (2) real world merchandise of some kind. They could create a platform for selling printed copies of images/photos on pintrest and they could take a cut of the revenues, and maybe even go into easy distribution and scale of physical products shown on pintrest with a cut of revenues as well. Probably other services they could combine with the content as well in other ways with some creativity.

Unless you can convince people to pay for your service, you can either openly use them as advertising platforms or you can be sneaky and sell your data to advertisers behind the scenes.

I cannot imply that advertising should be removed, unless the customer financially pays for the service - any company (especially public) will use advertising in some form, or else it is just lost revenue.

I guess the only other option would be to build paid services, like app.net, but that is a completely different revenue model.