Specifically when it comes to paid services, scripts, content purchases, hosting, etc?

For example, lets say you have a program owner, they buy all their content from the same content provider, they have hosted with the same host for years, their program uses a specific affiliate script, etc.

Now lets say you ask a question about one of those items and the program owner says 'yes its shit hot' to whatever your question was.

How do you know that you are being given and honest opinion and not an opinion based on them wanting to either...

1) Make their program seem better based on what 'they' are using?

2) Make their friends product seem better because they are 'friends'?

3) Make themselves seem better by saying something is good even if it isnt, because they dont want to admit they were wrong?

So as an adult webmaster, knowing the there are a bunch of individuals in the business that just say 'positive' stuff all the time, how do you judge whether their view/opinion is based on FACT and not just them trying to make themselves, their friends, their program look better?

Your thoughts?

Regards,

Lee