I signed up to PPH in my wide-eyed early days as an independent on the recommendation of some doofus or other but I've never followed anything up for exactly the reasons you describe; from what I could gather at the time, opportunities to provide the moon on a stick by tomorrow morning (Budget: £10-20) made up the better part of the norm. Things may have changed since then and it appears to be a popular community but the PPH business model creates a massively unequal relationship between procurement and supply in favour of the latter.
Okay for those after a bit of pin money perhaps but no way to build a business.