Praise be to Allah.
It is not permissible to seek the help of an unveiled, adorned woman for the purpose of marketing and advertising, because that comes under the heading of helping in spreading tabarruj (wanton display) and causing people to look at haraam things. Allah, may He be exalted, says (interpretation of the meaning): “And cooperate in righteousness and piety, but do not cooperate in sin and aggression. And fear Allah ; indeed, Allah is severe in penalty” [al-Maa’idah 5:2].
Tabarruj (wanton display) is a major sin. The Prophet (blessings and peace of Allah be upon him) said: “There are two types of the people of Hell whom I have not seen: men with whips like the tails of cattle with which they strike the people, and women who are clothed yet naked, mumeelaat maa’ilaat (walking with an enticing gait; or turning away from righteousness and leading others astray), with their heads like the humps of camels leaning to one side. They will not enter Paradise nor smell its fragrance, and its fragrance may be detected from such and such a distance.” Narrated by Muslim (2128).
What good can a person attain if he gives reasons for these people to show their images on social media – when they deserve to be ignored and kept at bay – and sponsors them to do that, when some people are tempted by looking at them? So think about all these infractions, and you will realize how bad it is to seek the help of these people in advertising. You should be certain that your provision is decreed and will never be decreased if you avoid what is haraam. In fact, a person could be deprived of some provision and earnings because of sin. The Prophet (blessings and peace of Allah be upon him) said: “A man could be deprived of provision for a sin that he commits.” Narrated by Ahmad (22386) and Ibn Maajah (4022); classed as hasan by al-Albaani in Saheeh Ibn Maajah.
And the Prophet (blessings and peace of Allah be upon him) said: “The Holy Spirit (Jibreel) has inspired to me that no soul will die until it has completed its appointed term and received its provision in full, so fear Allah and do not be desperate in seeking provision, and no one of you should be tempted to seek provision by means of committing sin if it is slow in coming to him, for that which is with Allah can only be attained by obeying Him.” Narrated by Abu Na’eem in al-Hilyah from the hadeeth of Abu Umaamah; classed as saheeh by al-Albaani in Saheeh al-Jaami‘, no. 2085.
See also the answer to question no. 231070.
And Allah knows best.