Jakob Nielsen always has good advice in his Alertbox newsletter and this week’s article called Designing Web Ads Using Click-Through Data is no exception.

Jakob offers some interesting real world experiences on running a text ad on Google. I think the analysis is spot on, suggesting that aligning the ads goal with the user’s goal in visiting the page make the ad more effective. I’ve been talking about building context into online marketing for a while now and this is a great example.

One exception I take is that Nielsen feels this is only effective on search engine results pages. I think context will improve an ad on any page on any site, and it will be of particular value on pages that people go to for help. If I’m looking for information on getting stains out of clothes and see a link to download the Tide Stain Detective on my PDA so I’ll always have this information on my finger tips, that ad is in context and should out-perform generic “run of site” ads.

I’d also suggest that the Tide Stain Detective download would also do well to advertise on Palm app download pages. The last place I would go would be a cooking page based on the assumption that whoever is cooking is also doing the laundry and will therefore be interested. This is weak context.