I am not in charge of making such decisions, but here are some general guidelines.
Post info about items For Sale in the For Sale section.
Offer technical assistance for your products in specific threads requesting same and in your company-specific section of the board.
Please feel free to also do the above in threads and sections not specific to your brand, but ALWAYS identify yourself as a company rep.
What is NOT ACCEPTABLE - "We here at BestEbikeCo solve that problem with our Super Whizzo 3000." That is just advertising, and that belongs in the For Sale section.
What IS Acceptable - "while we at BestEbikeCo think our Super Whizzo 3000 is the best solution to this problem, here are a few alternate methods which may help this particular user."
Also, being from Canada, you are required to end every sentence with "Eh", ya hoser.