[Toby]

It looks like you're relying mostly on toplists and search engines for traffic. The quality is usually good, but building volume is very difficult.

Setting up an affiliate program is one solution, but there's quite a lot involved. The billing part is usually pretty simple, most processors have a ready made solution available. Setting up and maintaining promo content for affiliates (zips, hosted galleries, banners, etc.) is time consuming, but without them you won't get many affiliates to promote your site.

Here are some additional options:
Paid ads (banner or text link) on high traffic sites with niche relevant traffic, a nylon niche TGP for example.

Submit galleries to niche relevant TGP's.

Contact review sites about adding a review of your site.

Open your own TGP and list your own galleries, banners, etc. along with sponsor galleries. You don't even have to take outside submits if you don't want to deal with it. The key there is setting up traffic trades with other similar TGP's.

All of these take time, energy and money. The easy money days are long gone.