TDA has been tasked to increase traffic and secure new donors for the website during the run-up to Christmas. Running from early November, the campaign will involve a range of channels including email activity, online display advertising and paid and natural search.
Cows 'n' Things sells ethical gifts that are given to the elderly in developing countries. Some items include mosquito nets, cataracts operations and cows, all ranging from £5 to £400 per gift.
Sam Hemming, fundraising manager for Cows 'n' Things, said: "TDA's strategic response to our digital brief really stood out. Founded on strong direct marketing technique, its recommendations involve well-targeted creative executions that are built on strong digital understanding and financial accountability."
TDA has previously worked for charities including St Dunstan's, The National Trust and The Parkinson's Disease Society.