I have spent the last couple of weeks thinking about and testing some of the best known digital payments systems currently available or under development in the US - Google Wallet, PayPal, Square, V.me and PayPass Wallet Services.  

Having just recently moved to the Bay Area from London, where - except for PayPal - they are not available, it is actually exciting to have the opportunity to play around with them.

 So, in the next few posts, I will be providing an in-depth look at how each of these digital wallets works and how valuable they are to the key players in the ecosystem.  In order to allow for comparison across the different solutions, I will use the following criteria (taken from The Smart Card Alliance White Paper titled 'The Mobile Payments and NFC Landscape:  A U.S. Perspective') applied to consumers, merchants, MNOs and issuers.1)  Reliability at POS:  Transactions that work every time and that are fast, robust and reliable.
2)  Security:  Keeping safe credentials and transaction information is paramount.
3)  Ease-of-use and convenience:  Key to promote adoption among consumers and merchants.
4)  Wallet functionality:  Ability to easily store and use different payment methods by amount or merchant, transfer info to a new phone, enable preferred payment instruments and establish branding.
5)  Acceptance at Merchants:  Particularly at day-to-day stores, along with all other payment methods.
6)  Device deployment/availability:  Available across most phones independent of manufacturer, Mobile Network Operator (MNO) and Operating System (OS).
7)  Value-add apps:  Most wallets are being built as open (or semi-open) platforms to enable companies to develop apps on top of them. The idea is to have, at the end of this series, an easy-to-read table that will compare how each digital wallet ranks on each criterium.  Digital wallets are constantly evolving so the information I post may soon be out of date.  I plan to update it as this happens.  Also, I will be analyzing some systems that have not yet been fully launched and some others for which we don't have full information on their inner workings, which will force me to make assumptions.  Again, if my assumptions are not accurate,I will update the post as new information comes available.  As always, I welcome any comments or info that correct any misconceptions and increase the value of the articles.