Derek Gehl of the Internet Marketing Center has published a list of four areas website owners should be reviewing at least once a month to stay on top of their marketing efforts. Gehl makes specific recommendations how marketers should be analyzing their stats in the areas of traffic, sales and e-mail response rates.

In his most recent blog post, Derek Gehl points to the benefits of Google Checkout over PayPal, including its cheaper transaction fees and greater speed. Gehl also speculates what Google's motives may be by introducing Google Checkout, and what the company could do with the new commerce data it's collecting. Read his full commentary here.

Derek Gehl advises that regardless of whether you're a blogger, selling an information product or an eBay auctioneer, pictures are able to "show off your product in ways that words simply can't." Gehl explains the benefits of pictures for different web site types on his blog here.

Derek Gehl posts on his blog the five most common mistakes people make when designing their site's navigation. Gehl points out that the most polished site in the world will do you no good if your visitors cannot find what they're looking for. Read Gehl's 5 navigation mistakes and how to avoid them here.

In his latest blog post, Gehl talks about a search engine for podcasts, called PodZinger, and how it is better than traditional search engines.