Trade shows are to be all business, do not get caught up with any negativity of other vendors, stay alert, bright and positive.You have spent a lot of money and you must make $cents. 
 
You'll find other vendors complain from day one about the lack of traffic and the big expense.Make every lead count and turn them into sales, no matter how much there is ? Do not get caught up in what others do ! Be the best you can be always.

Odd cartoon enough. Trade show lead generation starts before the event, you can't always rely on the people sent to the show. And, why is Joe by himself? 
 
 
 
Best, 
 
 
 
Justin

Here here to the tips above. 
 
I'd also add: remember to get the business cards or at least the names of the folks you are having drinks with. I like to maintain a ratio of 1 name per drink (to avoid hangover's remorse). Chances are one of your best leads/contacts will come out of the social time spent outside of the exposition hall.

This cartoon reminds me of one of my direct competitors (Also a family memember). They recently opted to appear in a local remodeling trade show. They spent big bucks and never even realized trade show attendance has been plummeting.

Sometimes it's better to have fewer but better leads than a whole lot of names that amounts to nothing.

The first question you have to ask yourself is: will my company be missed by NOT being at the trade show? 
 
If the answer is yes, then go - and make every penny count and make every visitor to your stand count.  
 
Most importantly as @Marc says make sure you get business cards or at least contact details - and follow up promptly. 
 

Joe's VP should have bought the virtual exhibition option. Their inbound marketing isn't affected by visitors:  
board meeting, slashed marketing budget or only the 3 day window the physical event offers. And, Joe can enjoy a social drink without having to worry about how his boozy comments can be distorted by the competition.

Trade shows aren't at the top of my list of lead gen activities, but if executed correctly with the right audience, you'll keep Joe busy and get some business. 
 
Small, targeted events can pay off. You may not get as many leads as at a global event like Cebit, but the quality will be higher. 
 
Target the same events, pubs and sites as your prospects to improve lead quality. Too often we confuse quantity and quality.  
 
As Willy Sutton said when asked why he robs banks - "cause that's where the money is." 
 
Also, if you let Joe out the office more often he may not feel the need to get all his partying done at one event.

I gave up on having a trade show boot. I even wrote a blog, "Trade shows,are they for Civil Engineers". I get more leads by wandering through the trade show.