But let's say you do and get 20 signed up as advertisers. Who cares? It won't earn you a cent until you get users in the door, you'll get worse terms, and it won't help you improve the underlying product.
Your users are the leverage you have to make good deals with advertisers.
beta launch: d) Display content of preferred partners who list us as elite partners on their site
public launch: f) Consider exclusive partnerships on specific things, ie. Wells Fargo for banking, T-mobile for cell phones.
This is very roughly written plan, but it covers almost everything required in early phases. The focus was mostly on creating a user base, but it is important that you work on all and start doing baby steps. Most new startups don't cover all the bases and wonder why it isn't working! :)