Could just be sloppy use of the English language but why use the word "would" (which implies a "but...") when using "will" was the more definitive option?
e.g.
Are you going to the party?
I would go (but....)
Yes, I will go
The article is saying that 70% of Saints use saintsfc.co.uk as their first port of call for Saints news.
This doesn't necessarily mean that the other 30% "don't use" (quote/unquote) the official site in any shape or form. They may just not use it as their first port of call for Saints news.
How can you be sure that Tescos will get planning permission for that many new stores in the region?
Edit: sorry, cheap 'laugh'....but will keep it in though just in case someone finds it vaguely amusing....