What a coincidence! Just a day after Google announced that it would be launching a new venture designed to sell e-books online, Amazon unveiled a similar plan. Saying that its Web-based application would be available “in the coming months,” Amazon outlined a service that would allow users to buy books online without needing a Kindle to read them. That strategy is reminiscent of Google’s rollout, which sells books that can be read in any Web browser. Let the competition begin.