I unexpectedly got 20,000+ u/hits from StumbleUpon to a dynamic PHP page last year on a shared hosting account and there wasn't even a blip - how much traffic a

I unexpectedly got 20,000+ u/hits from StumbleUpon to a dynamic PHP page last year on a shared hosting account and there wasn't even a blip - how much traffic are you expecting exactly? I just wonder if you're unnecessarily wasting effort..