The combination of smarter customers and increased use of the Internet in Mexico means that the Internet is now an important competitive weapon to acquire new customers and also to retain existing customers. Previous research into online strategies in banking has tended to focus on either high-level strategic outcomes or on internal web data that is specific to a particular bank. In this paper, online panel data is used to generate insights into consumer behavior and bank performance in the key areas of share of online search, share of e-service and overall levels of e-banking. It is shown that the market leader Banamex is underperforming in the online channel relative to its market share. In contrast, the online attackers HSBC and Scotiabank are very strong in terms of their Internet performance. By distinguishing online activity into two groups, search and e-service, it is shown that smaller banks have an inherent advantage in online markets for customers searching out a new banking relationship – this is termed the ‘online attacker advantage’. The theoretical and managerial implications are outlined for the use of panel data generally and the results of the analysis concerning the Mexican banking industry specifically.