Now a general rule of thumb amongst SEOs when scoping out link opportunities is to find pages with less than 100 links. Obviously this page far more links than that. But don't worry, here's an explanation from Google's Matt Cutts himself:
Matt's exact words - The "keep the number of links to under 100" is in the technical guideline section, not the quality guidelines section. That means we're not going to remove a page if you have 101 or 102 links on the page. Think of this more as a rule of thumb. Originally, Google only indexed the first 100 kilobytes or so of web documents, so keeping the number of links under 100 was a good way to ensure that all those links would be seen by Google. These days I believe we index deeper within documents, so that's less of an issue. But it is true that if users see 250 or 300 links on a page, that page is probably not as useful for them, so it's a good idea to break a large list of links down (e.g. by category, topic, alphabetically, or chronologically) into multiple pages so that your links don't overwhelm regular users.
I would imagine Google is going to crawl its own pages as far as they go. Yes, if you understand the Page Rank concept that "link juice" is divided among all the links on the page - the more links the less nectar you get. But Page Rank is exponential. 100 links on a Page Rank 8 page could pass more value than 50 links on a PR4. If I'm wrong here, please drop a comment.
It can only help you to get a link from this page. And it could send you good traffic from Google Checkout fanboys and girls as Google heavily promotes its payment service and continues to offer special deals -- especially around the holidays (10% off purchase, for example).
Offering alternative payment options also accommodates shoppers who don't want to provide credit card information to every merchant and prefer to give this information to one party, like Google Checkout, and complete transactions at many stores quickly.
You also get a bit of kickback on your Adwords fees when you participate with Google Checkout. And some report higher click throughs after adding Google Checkout because the icon that appears in PPC results attracts more attention, especially when you're in lower positions. Jeremy comments at Search Engine Roundtable:
Just by adding the icons to the PPC ads, I did not see conversions rates go up, but still, increased traffic with the same conversion rates equals more sales.
Hey, notice the dynamic keyword insertion goof on the last result? Triple check your ads and display URLs before they go live...