Help me build a simple manual affiliate tracking system. Built upon my existing tracking and analytics systems. 

AFFILIATE LINK GENERATION:
- Create unique tracking links for each affiliate: yoursite.com/?aff=partner-name
- When someone visits these links, capture the 'aff' parameter
- Store affiliate attribution in existing traffic_sources table
- Track all signups and purchases back to the affiliate who referred them

SALES TRACKING:
- When a purchase happens, check if there's affiliate attribution
- Calculate commission based on sale amount and agreed percentage. Ask me for the % breakdowns.
- Log commission owed in affiliate_commissions table
- Flag for manual payout processing


BASIC TRACKING TABLES:
- affiliates: partner info, commission rate, contact details, status
- affiliate_commissions: sale_id, affiliate_id, commission_amount, payout_status
- Integration with existing analytics 

Keep it simple - manual payouts, basic tracking, no automation complexity.