Sell More, Play Less: Benchmarking LLM Realistic Selling Skill
Authors: Xuanbo Su, Wenhao Hu, Le Zhan, Yuting Xie, Kailin Lyu, Kaijie Chen, Ziwei Li, Yeqiang Wang, Haibo Su, Yunzhang Chen, Ling Huang
Organizations: Bairong Inc. · Institute of Automation, Chinese Academy of Sciences · Zhongguancun Academy · Tongji University · King Abdullah University of Science and Technology · Shanghai Jiao Tong University · Shanghai Innovation Institute
Sales dialogues require multi-turn, goal-directed persuasion under asymmetric incentives, which makes them a challenging setting for large language models (LLMs). Yet existing dialogue benchmarks rarely measure deal progression and outcomes. We introduce SalesLLM benchmark, a bilingual (ZH/EN) benchmark derived from realistic applications covering Financial Services and Consumer Goods, built from 30,074 scripted configurations and 1,805 curated multi-turn scenarios with controllable difficulty and personas. We propose a fully automatic evaluation pipeline that combines (i) an LLM judge for sales-process progress, and (ii) fine-tuned BERT classifiers for end-of-dialogue buying intent. To improve simulation fidelity, we train a user model, CustomerLM, with SFT and DPO on 8,000+ crowdworker-involved sales conversations, reducing role inversion from 17.44% (GPT-4o) to 8.8%. SalesLLM benchmark scores correlate strongly with human ratings (average Pearson r=0.86; inter-annotator agreement Krippendorff's alpha=0.86, 500 annotations per model). Across 15 mainstream LLMs, in Chinese the strongest models are competitive with typical (junior-to-intermediate) human salespeople -- not with sales experts -- while weaker ones fall below this baseline, and cross-lingual consistency remains poor. SalesLLM benchmark serves as a scalable benchmark for outcome-oriented sales agents. Our code and data are released at https://github.com/Bairong-Xdynamics/Benchmarking-LLM-Realistic-Selling-Skill
Figures & tables
Figure 1: Overview of the SalesLLM benchmark: (1) Standardized Script Generation: Synthesizing role-play scripts by integrating product inventories, persona pools, and difficulty controls. (2) CustomerLM Development & Simulation: Training a specialized simulator via SFT and DPO to conduct simulated dialogues with evaluated sales LLMs. (3) Evaluation Pipeline: Evaluating sales performance through a dual-metric evaluation framework combining BERT-based intent classification for outcomes and LLM-as-a-judge scoring for process quality.
Figure 2: The Workflow of the Script Generation Pipeline. The construction process follows a logical transition from raw resources to synthesized scripts: (1) Raw Component Generation: The pipeline establishes three pillars: Product Information, where raw items are expanded into detailed profiles and deduplicated via MinHash; Persona Generation, involving the sampling of demographic attributes (Age, City, and Career); and the specification of Difficulty Profiles. (2) Persona-Product Pairing: The processed product-service pool is mapped to the sampled personas to form unique Persona-Product Pairs as the contextual foundation for the scenario. (3) LLM-based Information Synthesis: Based on these pairs and the assigned difficulty, LLMs generate the final scripts, including a User Script with product-specific motivations and pain points, alongside a Sales Script containing structured product features and selling points.
Difficulty
Avg. Score
# Scenarios
easy
6.79
2,779
medium
6.22
2,998
hard
5.45
1,219
very hard
5.33
3,320
adversarial
4.98
2,157
Table 1: Average SalesLLM benchmark scores by difficulty level, aggregated over Gemini-3-Flash, Qwen2.5-72B, Doubao-1.5-pro, DeepSeek-Chat, GLM-4.6, and Qwen3-Max. Difficulty is controlled solely through the customer’s system prompt.
Figure 3: The training pipeline of CustomerLM: (1) SFT on 8,000+ human-annotated sales dialogues to learn fundamental customer behaviors; (2) DPO using 268 contrastive pairs—refined through LLM judging and human correction—to suppress assistant-style bias and role inversion for enhanced persona consistency.
Intent classifier
ZH
EN
GPT-4o, zero-shot
69.60
68.85
GPT-4o, 10-shot
78.42
81.92
Fine-tuned BERT (ours)
93.51
92.94
Table 2: Prompt-controlled buying-intent classification (accuracy, %). Few-shot prompting helps GPT-4o substantially, yet a sizeable gap remains.
GPT-4o User
CustomerLM
Assistant Model
ZH
EN
ZH
EN
Doubao-1.5-pro-32k
6.50
6.31
6.89 †
5.48
Qwen3-Max
6.48
5.97
5.55
5.56
DeepSeek-Chat (V3.1)
6.74
6.10
7.03
5.80
GPT-4o
6.16
5.53
6.15
5.19
GLM-4-9B
6.01
5.92
7.14
5.55
Table 3: Overall performance (SalesLLM benchmark score) of different Assistant Models when evaluated against two user simulators: GPT-4o and our CustomerLM Model. Results are reported for both Chinese (ZH) and English (EN) scenarios. The best result is bolded, the second best is underlined, and the third best is marked with † .
Figure 4: Distribution of SalesLLM benchmark scores vs. dialogue turns across 1,805 scenarios (Chinese and English).
Figure 5: Correlation analysis between Human evaluation scores and SalesLLM benchmark scores. We evaluated four representative models, with 500 dialogues per model annotated by human experts. The overall average Pearson correlation coefficient is r=0.86 , demonstrating strong alignment between automated and human judgments.
GPT-4o User
CustomerLM
Assistant Model
ZH
EN
ZH
EN
Doubao-1.5-pro-32k
7.46
6.62
6.16
5.93
DeepSeek-Chat (V3.1)
6.47
6.96
6.24
5.67
Gemini-3-pro
7.17
7.03
6.56
5.95
Table 4: Performance of multi-product selling of different Assistant Models when evaluated against two user simulators: GPT-4o and our CustomerLM Model. Results are reported for both Chinese (ZH) and English (EN) scenarios.
GPT-4o User
CustomerLM
Assistant Model
ZH
EN
ZH
EN
Doubao-1.5-pro-32k
4.91
4.62
4.58
4.4
DeepSeek-Chat (V3.1)
4.58
4.48
5.92
5.82
Gemini-3-pro
4.43
4.58
6.20
4.88
Table 5: Performance of long horizon selling of different Assistant Models when evaluated against two user simulators: GPT-4o and our CustomerLM Model. Results are reported for both Chinese (ZH) and English (EN) scenarios.
Model
BLEU
R-L
Sem.
RI (%)
GPT-4o
0.10
0.07
0.57
17.44
UserLM
0.06
0.06
0.50
21.55
USP
0.08
0.08
0.52
18.76
CustomerLM
0.12
0.10
0.59
8.8
Table 6: Ablation study comparing CustomerLM with GPT-4o, UserLM, and USP as user models. R-L denotes ROUGE-L and RI denotes role inversion; higher is better except for RI.
Appendix figures & tables17 assets
Supplementary material from the paper’s appendix.
Appendix
Product
# Dialogues
Avg. Turns
Avg. Msg Len
Security
189
3.32
14.07
Banking
50
4.79
10.2
Fund
29
2.61
16.23
Appendix
Table B.1: The statistical information of CustomerLM test data. # Dialogues is the number of dialogues, Avg. Turns is the average turns of the dialogues, Avg. Msg Len is the average user message lengths.
Product
# Dialogues
Avg. Turns
Avg. Msg Len
Security
4748
2.3
16.25
Banking
1742
5.98
12.03
Fund
1794
5.42
11.97
Appendix
Table B.2: The statistical information of CustomerLM training data. # Dialogues is the number of dialogues, Avg. Turns is the average turns of the dialogues, Avg. Msg Len is the average number of words per user message.
Lang
#Dia
Avg msgs/conv
Avg user msgs
ZH (118_zh)
118
7.98
3.85
EN (150_en)
150
8.13
3.83
Appendix
Table B.3: Held-out ablation test set statistics (Sec. 4.5 ). Averages exclude the system prompt. Lang is language, Dia is dialogues.
Metric
GPT-4o
CustomerLM
N evaluated turns
750
751
History length
5.33
5.33
BLEU-4
0.1000 ± 0.1635
0.1218 ± 0.1749
ROUGE-1
0.0846 ± 0.1207
0.1062 ± 0.1499
ROUGE-2
0.0176 ± 0.0554
0.0250 ± 0.0790
ROUGE-L
0.0725 ± 0.1064
0.0985 ± 0.1414
Appendix
Table B.4: Turn-level user-likeness statistics on the held-out set (mean ± std; without “±”: mean). Best results are bolded.
Parameter
Value
Method
SFT / DPO
Training type
Full fine-tuning
Hardware
5 × A100 (80 GB)
Distributed training
DeepSpeed ZeRO-3
dtype
bfloat16
Epochs
2 / 1
Appendix
Table B.5: SFT/DPO training configuration for CustomerLM. Where two values are given, they correspond to SFT/DPO respectively.
Component
# Seeds
# Instances
E-commerce products
33
10,074
Financial services
300
20,000
User personas
–
19,138
Appendix
Table C.1: Statistics of the SalesLLM benchmark scenario space.
Category
#instances
Share (%)
Pet Supplies
392
3.89
Magazine Subscriptions
367
3.64
Patio Lawn and Garden
364
3.61
Office Products
361
3.58
Health and Personal Care
358
3.55
Sports and Outdoors
351
3.48
Appendix
Table C.2: Category distribution of the E-commerce scenario space in SalesLLM benchmark.
Category
# Instances
Share (%)
bank_deposits
10,521
52.61
stocks
6,109
30.55
insurance
2,858
14.29
bund_fund
512
2.56
Total
20,000
100.00
Appendix
Table C.3: Distribution of Financial Services categories.
Profile
Buy prop. pk
Buyer Prompt
easy
0.80
Open-minded, motivated buyer with clear pain points and flexible budget; decides quickly if the product is a plausible fit.
medium
0.50
Balanced buyer with concrete but resolvable concerns (e.g., price or fit); requires reasonable evidence and engages in moderate objection handling.
hard
0.20
Skeptical, price-sensitive, and risk-averse buyer; defaults to negative purchase intent unless strong, specific evidence and clear ROI are demonstrated.
very hard
0.10
Highly skeptical enterprise buyer with strict compliance and procurement constraints; requires detailed proof, references, and process alignment, typically postponing purchase.
adversarial
0.05
Adversarial evaluator primarily focused on disqualifying vendors; emphasizes edge cases, legal risk, and total cost of ownership, and almost never expresses positive purchase intent.
Appendix
Table C.4: Difficulty profiles used to control buy propensity and buyer style for the simulated customer.
Model
Lang
Acc
F1
GPT-4o (zero-shot)
ZH
69.60%
0.73
GPT-4o (10-shot)
ZH
78.42%
–
Trained BERT
ZH
93.51%
0.93
GPT-4o (zero-shot)
EN
68.85%
0.72
GPT-4o (10-shot)
EN
81.92%
–
Trained BERT
EN
92.94%
0.93
Appendix
Table E.1: Prompt-controlled accuracy comparison: fine-tuned BERT vs. GPT-4o under zero-shot and 10-shot prompting (Appendix L ). Lang is language (ZH is Chinese, EN is English), Acc is accuracy and F1 is F1 score.
Figure J.1: Decision Factor Distribution by Age Group. Stacked bars show the total number of decision-factor mentions ( Count ) for each age group in the SalesLLM benchmark persona set. Colors denote decision-factor categories (Return & Cost, Convenience & Digital, Fit & Flexibility, Safety & Protection, Support & Aftercare, Transparency & Terms, Social Proof, Brand Trust, Core Quality, Availability & Delivery), and the percentages inside each segment indicate that category’s share of mentions within the corresponding age group.
Figure K.1: Qualitative comparison: DeepSeek (Proactive) vs. GPT-4o (Passive).
Table M.2: Human–auto Pearson r within each difficulty tier.
Sub-dimension
r
Verbal purchase commitment
0.86
Concrete next-step alignment
0.79
Key information elicitation
0.80
Objection resolution effectiveness
0.82
Appendix
Table M.3: Auto-vs-human Pearson r per Selling Performance sub-dimension (definitions: Appendix P ).
Model
α=0.1
α=0.3
α=0.5
α=0.7
Doubao-1.5-pro-32k
0.748
0.749
0.746
0.678
DeepSeek-Chat
0.802
0.812
0.906
0.765
GPT-4o
0.831
0.829
0.910
0.731
Qwen3-Max
0.829
0.824
0.884
0.733
Average
0.802
0.804
0.862
0.727
Appendix
Table N.1: Pearson correlation ( r ) between automated SalesLLM benchmark scores and human judgments at different values of the weighting parameter α . Higher is better.