Occupationally I see post that I have products or services that would help based on what the person is asking about. Is it OK to send a privet message telling them how I can help?
Forums are only for discussions and debates. Whatever you have learnt you can discuss with the experts and learn more, by which the newbies can also join in and ask if they have any questions. For your question, you need to find some other place like Ebay or Amazon if you want to. One question to admin, can anyone talk and discuss about the making and breaking of his product ? Like his achievements and mistakes he came across while making the product ?
I fsomeone is looking for something, which you already providing then you can PM them and offer them your services. For instance if I am looking for an article writters, I expect people to PM me about their services.