I know that outbrain and taboola are the best, but I don't have a huge traffic to be accepted in that networks. So I need some alternative, where I can be accepted with a less traffic and get normal revenue. Any suggestions? : )
US traffic is good but since is not much I would recommend affiliate marketing, you know find related products to your niche and earn commissions, and here's a list with native ad networks http://www.ypayz.com/threads/list-with-best-native-ads-ad-networks.667/
Aff Marketing is not for me and for my website I don't write recommendations or product reviews on my website, so don't think it'll work. btw my website is about Traveling.
There's https://www.tripadvisor.com/Affiliates and http://www.expediaaffiliate.com/ with travel offers and very high commissions.