All portal sites generate revenue from banner advertising. One way or another your content will have an advertisement on it. However, some sites will sell sponsorships to sections of their websites. If a major corporation sponsors an exhibition, and the content on the portal site comes up as sponsored by the portal s sponsor there is the potential for confusion. Another issue is how long will you allow the portal to use your content.
Most portal sites view themselves as new versions of Hollywood studios.
It is important to spell out a term period for use of the museum s materials. One suggestion is give use of the content for the duration of the exhibition, plus a few months. The additional time allows people looking for the exhibition after it closes to know that is indeed closed. Giving use of content is a great form of promotion, but you should also encourage the promotion to convert over to traffic to the museum s website. Be sure to make sure that the Portal links to your site.