Sudama, a poor Brahmana, was a childhood friend of Lord Krishna. Once he went to Dvaraka to meet the Lord. His wife managed to collect a few handful of flattened rice from the neighbours as a gift for Krishna. Sudama was reluctant to offer this humble gift to Krishna and was hiding the bundle of flattened rice. But Krishna grabbed the bundle and ate it with great pleasure. He also bestowed Sudama with all opulences.
If someone gives something to the Lord, he is not the loser; he is the gainer by a million times.
In Bhagavad-gita, Krishna says: If one offers Me with love and devotion a leaf, a flower, fruit or water, I will accept it. (9.26) Krishna is not in need of anything from anyone, because He is self-sufficient, and yet He accepts the offering of His devotee in an exchange of love and affection.
Sudama Seva is an opportunity for devotees to make their humble offering with love and devotion at the lotus feet of the Lord. You can commit for a monthly, quarterly or annual donation according to your capacity.