It may be hype, but when MongoDB was released, what other RDBMS was offering the same functionality? I see Posgresql + JSON mentioned, but when was JSON support added?

I personally like MongoDB for: - flexible schema (less migration pain) - easy tags implementation - product attributes (list of name-value pairs) - GridFS - store binary files - nested documents for analytics (ex: a record for each day with a nested doc for each hour)

I wish MongoDB had - some support of join - multi-master replication

I personally used MongoDB as primary storage (yeay dot me), but currently prefer it as secondary storage.

As any product it evolves and I expect to see more improvements. I think MongoDB brought NoSQL to the masses :)

Just my 0.02. Thanks.