I was looking at buying tickets early online for Pompeii Scavi. The tickets indicate entrance at Piazza Anfiteatro, not Porta Marina - which Rick Steves says is the best entrance. It looks like it is much further from the train station to that entrance. Has anyone bought tickets early on line? Are the ticket lines long? Is it necessary to get tickets early to skip the line?
If you want to skip the line to purchase tickets on the day, quite obviously you must get entrance tickets online in advance. Then there is the security line and nobody skips it. Then you are in.
I could be wrong (it happens) . . . .
My understanding is that Piazza Anfiteatro is the closest entrance from the City of Pompei train station - about a 10 minute walk. It is not used much, since most people use the Circumvesuviana/Campania Express which is just a few meters from the Porta Marina (main) entrance. The anfiteatro is quite a walk from the there, in most places the Romans built the amphitheatres well outside the city center because of the crowds of people - much like modern arenas.
The line would probably only be as long as the number of people who got off the train with you.
When we were at Pompeii a couple of weeks ago there was no line for tickets at all and also no security. We just walked up to the window, purchased tickets and walked to the turnstiles where our tickets were scanned and in we went. However, many of the most interesting sites inside were still closed (baths etc), perhaps due to being early in the season.