1.)Is serving images via blobstore a good idea in regards to SEO of my application? As all my images are going to dynamic, does google index dynamic images with my custom domain url.
不要将图像放入数据库。而是上传图像并将链接放入数据库中。Instagram 将 s3 用于其图像,因此您不必担心性能。如果您将图像存储为文件并提供链接,搜索引擎可以很好地索引它们。只需确保为图像使用相关名称即可。例如,对于此图像,请使用http://example.com/data/image-store/owl-be-your-valentine
3.)And please suggest if there is any other alternative that is better that GAE and can serve my requirements.
我没有用过GAE。如果您要求替代方案。我建议你aws s3。
2.)And image serving is going to cost outgoing bandwidth which seems too be cheap but still is there any other alternative to cut off outgoing bandwidth cost?
s3很便宜,很便宜。http://www.codinghorror.com/blog/2007/03/using-amazon-s3-as-an-image-hosting-service.html