As far as NPS goes, it depends on how you use it. If you sign an agreement with a rod manufacturer who gives you 30% off of their rods, and a t-shirt provided you: buy a minimum of 5 of their rods within 15 days, use their rods exclusively in tournaments, wear their logo at every weigh-in, have their logo on your boat and truck, document contacts with local tackle shops where you are trying to get their products into the store and everything else you do to promote their product, make yourself available for two weekends a year for trade shows, and put a bunch of time into your youtube, facebook, twitter and other social media accounts, you better be a fan of those rods anyway and plan on buying the maximum number of rods at the discount to make that investment of your time worth the money you actually save. I see a lot of guys selling off all of their current rods, that I know they like, to get money to buy the rods from the sponsor, and because they can't use the old rods in tournaments anymore per the agreement.
On the other hand, some of the smaller companies on NPS seem to be getting their business exclusively from people who agree to NPS "pro-staff" deals. They'll take anyone who will apply and give them a discount on product that is so overpriced I can't imagine anyone is paying retail. Plus most of these companies charge shipping for their stuff, something a lot of people forget about, versus a decent size TW order. Sometimes, you don't have to sign any kind of deal at all. You can buy as little or as much as you like. So I guess it doesn't kill you, but you still are expected to represent the company for the privilege of getting a "discount" on their expensive, somewhat obscure product.
Then there are probably people who really benefit from it who get on the pro-staff with companies where they would already be buying large quantities of product and are getting a legitimate discount. These are generally the more well known bait manufacturers who are a little more selective about who they will take. There are also probably better deals out there than the example given above that I haven't seen, particularly for more qualified people.
The bottom line is, NPS and the companies that use it have a pretty sweet little deal going. I'm not bashing the concept. Hell, I'm on NPS. It's fun to mess around on. I've applied for several "pro-staff" positions. I won't say who with, but I've turned down every offer I've received because once I've done the math after I considered how much product I'd actually purchase, I would be selling myself awfully cheap. So I've wasted money on applications, but I look at it as an entertainment expense. Maybe one will come along one day that I take.