I always thought that it's much more productive to spend more time trying to figure out what it is that SETI is looking for than scanning known frequencies for not-well-thought-through patterns.
We already probably would send out signals that SETI wouldn't be able to detect. How can they detect signals coming from entities whose mental architectures, computational powers, and command over physical world are dramatically different and superior to ours?
Why not create a good web of ideas about aliens instead?
Would cost a lot less money.
Except that people are much more comfortable searching for things they know. Alas, ETI is not among them.
[Should we suggest a few ideas to GIMPS + SETI?]