Does Adsense Content net you more $, or does Search? Which one has a better CTR? For me, Content gets me more money, but my Search, which is only on the main page, has a MUCH higher CTR - but has only earned me about 1/8 of content. So how bout you?
Content. People have already "found" you though search. If you lay your navigation out correctly most sites are not large enough to warrant an additional search.