I consider getting interviews a success.
At the beginning of august I was terminated because, the position was for a senior developer and I was more of an intermediate. Only because of my certifications I had interviews within 2 days and 3 offers in 3 more weeks.
Last week I received 15 emails, and 5 phone calls in a 3 day period for people wanting to interview me for intermediate
java developer posistions.
The cert may not get you the job, but it will get you infront of the manager and lets you differentiate yourself from other developers of the same level.