As I've said in some of my other reviews, the economic value of a card is the number of credits it gives you for doing things you would have been doing anyway. Sure Gamble gives you 4 for one click, which is 3 more than clicking for credits, so it has a value of 3. If you use Dirty Laundry to make a useful run, then you're getting a net gain of 3 for no extra cost--but if you make a throwaway run on an empty Archives, it's only a value of 2. With me so far?
Playing the first Exclusive Party costs you a click, and draws you a card. Assuming you would have clicked to draw that card anyway, that means you're getting your value back, and nothing else (remember: events don't go into your heap until they resolve.) So the first Exclusive Party has an economic value of 0. Gross.
But every one after that causes it to creep further and further up the economic tree. The second is as good as an Infiltration for cash. The third is an Easy Mark. The fourth is a Sure Gamble. The fifth is a cheaper Lucky Find. And the sixth is...well, there isn't a comparison, but it's damn good.
Since you have to get through the low-value versions first, another way to look at it would be the average value per card. Playing three Parties gives you 1 per play on average, four gives you 1.5, five gives you 2.0, and six gives you 2.5.
Looking at typical economy options, most players won't bother playing a card with an economic value below 2. Easy Mark (with a value of 2) does occasionally see play; we'll call that the minimum to be playable.
So to really justify including Exclusive Party, you need to be confident that you will see at least 5 of them per game, and 6 fairly frequently. Which basically means you need to be drawing your entire deck. Every game.
That's a big ask. Of course, many decks do draw their entire decks (LARLA sees play for a reason), and you're already going to be drawing through six of them with Exclusive Parties, but they just aren't enough. You are going to need some way to draw cards faster, whether that's Wyldside, Geist, or the brand new Patron.
Note, however, the anti-synergy with Professional Contacts and Symmetrical Visage. These cards don't draw you cards any faster, they just give you money when you do draw cards. Since this is the same effect as Exclusive Party, and they don't combine, you're better off picking one or the other.
So if you're already playing a draw-heavy deck, Exclusive Party lets you earn money as you slurp up your stack. But this brings us to the next issue: card slots.
See, there's enough diversity in the Netrunner card pool that you want to be able to counter whatever gets thrown at you. There are an enormous number of silver bullets, some of which (like Clot or Plascrete Carapace) are the only thing standing between success and failure against certain decks. Including six Exclusive Parties means you have six less slots to spend on these cards. But having less than six means you won't see enough of them to be worth including at all.
So I guess the conclusion is this: if you're playing a slow archetype that wants to draw its entire stack every game, and you're okay having fewer deckbuilding options, and you're either in Criminal or have six influence to spare, maybe try Exclusive Party.