I hear "sponsored links" mentioned a lot as being a great, low-cost/high-impact, alternative to banner ads. But I rarely see examples of sponsored links on a site that are, well, clickworthy (or even noticeable.) Then I was playing, eerrm, doing research on gURL.com
and was very impressed with how positively the sponsored links are included in the site.
In fact the links feel valuable, partly because the sponsor's copywriting is generally excellent (with benefits-based headlines), and also because marketers using them have targeted the exact section of the gURL site they want to sponsor. For example, after you finish playing (errm, researching) gURL's "Make Your Own Reality TV Show Game", a pop-up box appears with three tv-related offers. And, as you scroll through the offerings in the "Looks aren't everything: a love/hate look at beauty culture" site area, there's a whole cool-black area for "Sponsored Fashion Links" which you can't help but read over. You can buy gURL.com links via About's Sprinks system.
If you plan to buy any other Sprinks links, I suggest you check out copywriting at gURL.com's links to get ideas first. It's those little, tiny copy blocks that are always the hardest to write!