So.. I'm selling advertisment spots on http://www.digitheme.com (a technology-related blog).

Links starting from $3/month, Banners starting from $5/month.

Additional packages:
6 month ads - $20
1 year ads - $35
Lifetime ads - $50 (the domain and webhost were allready paid for 3 years).

You'll find any other info you need (including statistics, prices and plans) on http://www.digitheme.com/advertise/

Notes: Payments are made via PayPal only. You'll receive a report at the end of each month containing the impressions and the click rate.

Links and banners should refer to the same niche or at least similar niches.