The Three Design Decisions - Choose Two
Someone on Twitter made a comment about a replication solution being expensive. That particular solution is expensive, but I think that expense is relative to the problem you're trying to solve.
Something I always tell my customers when designing solutions is "You can have availability, performance, or an inexpensive solution. Choose two." That's right, no matter how hard you try you can't have all three. Each slice of the pie requires sacrifice of another piece.
I'd love to hear your thoughts...