Link Unit Searchbox

What happens when no links are displayed?

[Shiznaught]

My question is about the link unit part of adsense. What happens when no context relevant links are displayed and the searchbox appears? Do you get credit if someone makes a search and then clicks an ad?

When this happens to a conventional ad unit, a charity ad is served up, so I'm wondering what the deal is when no relevant ads are served for link units.

[Jenstar]

Do you get credit if someone makes a search and then clicks an ad?

Yes.

[Shiznaught]

so is this a viable way of generating ad revenue?