From my perspective it depends on whether there's anything worth watching on 'proper' television, in which case I switch channels and that is that. If I'm really bored I stick with the tanzanite lecture for a minute or two depending on who's presenting it at the time, then if I'm also doing other things I may leave it on in the background just to see what prices the items sell for.
Is it me or do the first one or two tanzanite items often sell for higher prices than the later ones, though admittedly I'm not usually <del>mad</del> bored enough to keep watching in order to check these things? Perhaps if they sell a lot of different tanzanite items then only the more committed and knowledgable buyers are still watching after a while, therefore prices start to become more realistic, though the final price can also depend on the style of item and the stone sizes (namely if they're not mine floor sweepings).