Courts increasingly rely on analogies to show that claims are not directed to patent-eligible subject matter under 35 U.S.C. § 101. For example, in Context Extraction and Transmission v. Wells Fargo Bank, the Federal Circuit found that the claimed method of information processing was analogous to the way that “banks have, for some time, reviewed checks, recognized relevant data such as the amount, account number, and identity of account holder, and stored that information in their records.”  In Affinity Labs v. Amazon.com, the Federal Circuit found that the claimed method for streaming wireless media was analogous to previously-known “dial-a-joke” telephone services.  In Intellectual Ventures I v. Symantec, the Federal Circuit found that the claimed method for filtering emails was analogous to situations in which “people receiving paper mail” would “look at an envelope and discard certain letters, without opening them, from sources from which they did not wish to receive mail based on characteristics of the mail.” 
While courts have generally analogized to activities that are old and well-known, the fact that an activity is old does not necessarily make it abstract. Rather, abstractness requires a lack of technological specificity. Indeed, when the Federal Circuit has upheld claims under § 101, it has consistently explained that the claims are directed to a technology-specific problem and solution. For example, in Enfish v. Microsoft, the court found that the claims at issue were patent-eligible because they were “directed to a specific implementation of a solution to a problem in the software arts.” 
Courts may find a sound analogy persuasive because it can demonstrate that a claimed solution is not technology-specific, and is therefore abstract. For example, if an analogy shows that all steps of a method claim were performed on paper before the invention of computers, then a court may conclude that the claimed solution is not computer-specific.
To overcome a challenger’s analogy, a patentee can show how the analogy fails to capture meaningful limitations of the challenged claims. In DDR Holdings v. Hotels.com, the dissent argued that “the ‘store within a store’ concept, such as a warehouse store that contains a kiosk for selling a third-party partner’s cruise vacation packages, is the pre-Internet analog” of the challenged claims.  The majority rejected this analogy because it failed to account for the unique behavior of Internet hyperlinks, which the challenged claims required. 
The strongest analogies will account for every limitation of a challenged claim. However, a challenger may still succeed in invalidating the claim even if the analogy fails to address several limitations. For example, the analogy may correspond to an abstract idea at step one of the Alice framework, while additional limitations may be addressed separately at step two.  If the additional limitations beyond the analogy (and therefore beyond the abstract idea) require only routine and conventional computer functions, for example, then those additional limitations may fail to make the claim patent-eligible under Alice.
The case law governing § 101 is notoriously difficult to apply, but a compelling analogy can cut through the uncertainty and convince a court to invalidate a challenged claim without attempting to precisely discern the dividing line between eligible and ineligible subject matter. Patent challengers may therefore find it beneficial to offer analogies when attempting to invalidate claims. To defend against such attempts, patentees should be prepared to distinguish their claims from the alleged analogies and to explain how the distinctions they identify reflect a technology-specific problem and solution.