It's certainly one of the better ideas for that purpose. I like to imagine, though, that the sufficiently advanced aliens, upon receiving the signal, would say

It's certainly one of the better ideas for that purpose. I like to imagine, though, that the sufficiently advanced aliens, upon receiving the signal, would say "huh, there's this weird low energy 1420Mhz emission coming from Sol. Guess we'll file it next to the other million aberrant emissions in the Local Group we can't explain."