From the terms of Service sticky at the top of the 5.0 Tech forum "Advertising Services
We do not allow people to post threads or to send private messages or emails to users here that advertise or solicit any products or services. Explicit advertising and soliciting in sigs is also prohibited. Exceptions include a one-time sale of a personal item or want posting within a member signature.
There is a HUGE difference between making your own writeup with pictures about a modification you've installed, and being an advertising agent for said product. Use common sense. DO NOT post links to vendor websites, post sales information, price lists, or vendor contact information. If a member asks you for this information in a thread, then ask that they PM their request to you.
Links to active E-bay auctions are also prohibited.
Once again... POSTING OF SALES INFORMATION IN THE DISCUSSION FORUM IS PROHIBITED. That is what we have a classifieds section for.
Vendors and advertisers should refer to www.drive9.com for information on how to advertise on this site.
We go to great lengths to keep solicitation out of the discussion forums so that members do not have to weed through thread after thread of advertisements and solicitations in order to participate in conversation about our hobby. So the rules apply to both vendors and forum members."
Either you chose to ignore the terms of service, or didn't bother to read them.