Google may not be the only licensee. They have no agreement with Stanford that says that.If you have any actual interest I can point you in the right direction so you can begin to understand why it doesn't matter if the original PageRank patent becomes public domain. In fact it hasn't mattered for a few years and that's based on fact and not FUD.
Try a couple of searches and see how the results are displayed. That way you'll know rather than guessing. It won't cost you anything, and probably not even attract a targeted ad. They won't know who you are if you have no Google account whereas some other companies with trackers (on this very page!) well may and worse be more than willing to sell it.