Geez I wish people would figure this out: When Pictures Hurt Websites
The company has found that when placed on Web pages, images can act as barriers to action rather than the sort of eye candy that generates sales when placed on magazine covers. Users don’t just ignore them; they try to look around them. Worse, when action buttons (or “triggers”) such as subscription fields or purchase links are placed near or even on those images, users look straight past those too then click away.
It's not just potential customers clicking away: it's learners, readers, everyone. The message is simple: Put up nonsense content-- send your visitors away.
Of course, we've known this for a long time. If you are putting any content on your Web site that doesn't add absolute value to the conversation then leave it out.