Getting more ads posted on my portal ?

Hello,

I have a business portal which has reached 15k users by now. I want to have more and more users post their ads on this portal.

For this, I have done SEO to much extent and the result is 15k users in a year.

What will be the best way of getting more traffic with posting on my portal:

- Putting ads manually
- Cold calling
- Email newsletter (which I think becoming obsolete now b'coz people avoid them as spam)
- Other

Please suggest.

TIA

I'm confused. Let me get this right: You have a business portal were businesses can create their firm for free, and then they can also pay to get som advertisement?

I'm 100% sure they are only doing it for their link, and only a stupid business owner would waste money on ads, on a business portal.

Rasmusk, I think you did not understand my query properly.

I want to fill my portal with the business listing so that people can easily search them through search engines and get my site high traffic. I've kept this portal open for all those business owners who want to list their businesses and promote them. But I feel this process becoming very slow.

I'm looking for the ways to have my portal updated with those listings very frequently.

I hope this is more clear now.

Rasmusk, I think you did not understand my query properly.

I want to fill my portal with the business listing so that people can easily search them through search engines and get my site high traffic. I've kept this portal open for all those business owners who want to list their businesses and promote them. But I feel this process becoming very slow.

I'm looking for the ways to have my portal updated with those listings very frequently.

I hope this is more clear now.