Christ will remember even the smallest gift given. Paul and the Holy Spirit commend the Philippian church as a model in terms of their giving spirit. Despite the fact that they are a young congregation they understood the importance of faithfully and consistently giving to front-line ministries.
Paul acknowledged the giving was also proof of the love the church had for him. When we reach out to meet physical/practical needs it is a manifestation of the love of Christ.
They had a passion and commitment to the gospel so giving generously to Paul was also because they were disciples. The whole congregation gave generously and sacrificially. Giving is a demonstration that God is a priority.