According to the interpretations I'm most familiar with (mainly fundamentalist/Evangelical Churches, such as Baptist and non-denominational "Bible churches") the answer is "It's all-inclusive". it includes anything and everything we can do to help others, demonstrate love, and see to their needs. Financially, spiritually, emotionally, every possible way.
This stems from basic Biblical principles and application of passages such as the following:
Colossians 3:22-24 (KJV)
22 Servants, obey in all things your masters according to the flesh;
not with eyeservice, as menpleasers; but in singleness of heart,
fearing God: 23 And whatsoever ye do, do it heartily, as to the Lord,
and not unto men; 24 Knowing that of the Lord ye shall receive the
reward of the inheritance: for ye serve the Lord Christ.
The interpretation being that we are to serve others at all times because doing so is also service to the Lord. We honor God in all acts of service.
Also taking in mind that service is an expression of love:
Mark 12:30-31 (KJV)
30 And thou shalt love the Lord thy God with all thy heart, and with
all thy soul, and with all thy mind, and with all thy strength: this
is the first commandment. 31 And the second is like, namely this, Thou
shalt love thy neighbour as thyself. There is none other commandment
greater than these.
Matthew 5:46-48 (KJV)
43 Ye have heard that it hath been said, Thou shalt love thy neighbour,
and hate thine enemy. 44 But I say unto you, Love your enemies, bless
them that curse you, do good to them that hate you, and pray for them
which despitefully use you, and persecute you; 45 That ye may be the
children of your Father which is in heaven: for he maketh his sun to
rise on the evil and on the good, and sendeth rain on the just and on
the unjust. 46 For if ye love them which love you, what reward have ye?
do not even the publicans the same? 47 And if ye salute your brethren
only, what do ye more than others? do not even the publicans so? 48Be
ye therefore perfect, even as your Father which is in heaven is
If service is an expression of love, and we are to love our enemies as much as our neighbors, it follows that we are to serve without reservation, even those that we find despicable.
Long story short, there is no Biblical reason to expect that there is a limit to how we are to serve. We should follow Christ's example, and put others before ourselves, as the ultimate expression of Agape love.
More on the subject from the same perspective can be found at Christia.Net
Christ is the best example of demonstrating Christian servanthood the
way it is meant to be in God's eyes. Being a true servant is seeing
people as opportunity for a relationship rather than just as needy
people we walk by every day. Being able to see them with Christ's eyes
will show them His presence within the depths of our hearts. Serving
others is one of the most effective ways to lead them to the Lord.
Many forget or ignore this command of the Christian life, but it is
best to show others Christ through actions rather than words. "Let
nothing be done through strife or vainglory; but in lowliness of mind
let each esteem other better than themselves. Look not every man on
his own things, but every man also on the things of others. Let this
mind be in you, which was also in Christ Jesus: Who...made himself of
no reputation, and took upon him the form of a servant" (Philippians