One additional last thought:

I shall get to the bottom of my no sales mystery with PayPal, it's not up to you to solve their problems

Your HTML for the Paypal button to buy a product appears correct. As long as you have that HTML on your website, and it does take the potential buyer to Paypal, where they can choose to pay via credit card or Paypal (as I've demonstrated when I tested it out), then I don't think the lack of sales is a problem on Paypal's end. I think you just need to work on your website's marketing to get visitors to buy your product.

So for the meantime, this would be fine, as I have a sale and the buyer has the product, so main goal achieved, it's all a shop wants really.

Not necessarily true. A shop doesn't want the HTML page that includes a link for everyone and anyone to download their paid product to be accessible. I would implement PDT sooner rather than later, so that you can ensure that only people who paid for it can download it!

That's very generous, thank you, I realise that PDT - now you explain it, is the way for me to go with my Digital goods.
I have already looked into it, I may well seek your help, but I'll get as far as I can under my own steam as I realise there are others on here who need assistance and for yourself and your team there's only so many hours in the day. Many thanks, Steve

That's very generous, thank you

That's the purpose of DaniWeb! :)

I realise there are others on here who need assistance and for yourself and your team there's only so many hours in the day

DaniWeb is a community of members helping members. The best way you could give back, is by, as you learn, paying it forward by helping others in the future who may be struggling with things you've already figured out.

Be a part of the DaniWeb community

We're a friendly, industry-focused community of 1.21 million developers, IT pros, digital marketers, and technology enthusiasts learning and sharing knowledge.