Personalization is classically a two-party problem: a sender chooses what to say, and a receiver with independent objectives decides whether to act. A salesperson pitching the same analytics product leads with HIPAA compliance for a hospital and real-time reporting for a retailer, expecting a different argument to work on each. Existing LLM personalization benchmarks measure a narrower, one-party property: whether output matches the preferences of the same user it serves-sender and receiver being the same, as when RLHF aligns an assistant to its own user. The two-party case is harder to study automatically, since it needs ground truth linking specific content to an observed receiver action. Sales outreach provides this: a message written for one prospect, recorded against whether it produced a reply, a call, or a closed deal. We introduce SDR-Arena, a framework for benchmarking two-party generative personalization at scale, and SDR-Bench, a public corpus of 50,000 customer success stories across 22 industries and 3500 enterprises. Given only pre-outcome information, an agent must reconstruct the arguments that won the deal, scored by a weighted nugget-recall metric (WCS). The best model, Claude Sonnet 4.6, reaches 55.8% WCS indicating it recovers only half the winning content-a plateau we observe across model families that costly deep-research pipelines do not close. An ablation shows the cause is retrieval, not reasoning: models improve substantially given the facts a human researcher would gather, but rarely find them through web search alone. Two studies with professional SDRs support the metric: only 48% of generated pitches were rated usable without editing, and WCS yields model rankings consistent with evaluation against expert strategies authored independently of any model output.
Figures & tables
Figure 1: Overview of SDR-Arena showcasing how LLM generated output is compared with artifacts like Sales Emails, Transcripts & Success Stories to benchmark their personalization capability
Figure 2: Sales Journey: From Prospecting to Outreach to Call and eventual Deal Closure leading to Success Story publication
Figure 3
Model
Tech.
Mfg.
Energy
IT
Agg.
Search
Claude Sonnet 4.6
52.6
60.5
54.0
54.9
55.8
GPT-5.4-mini
40.99
46.02
41.18
45.39
44.63
GPT-5.4
38.21
45.46
42.90
46.67
44.32
STORM-QWEN-2.5
43.40
41.59
39.24
44.60
42.51
GPT-4o-mini
33.30
38.54
37.07
38.05
37.46
Table 1: SDR-Bench. WCS on success stories across four industries and on the whole set.
Model
Health. ( < $1B)
Tech. ( > $10B)
Calls
Search
Claude Sonnet 4.6
60.89
61.33
42.85
GPT-5.4-mini
43.67
52.66
35.72
GPT-5.4
48.71
53.02
33.61
STORM-QWEN-2.5
32.27
39.24
33.80
GPT-4o-mini
39.14
45.63
29.68
Table 2: Private Enterprise Dataset. WCS on successful outreach emails and sales call transcripts.
QWEN-2.5-72B
Claude Sonnet 4.6
Report supplied
Direct
+ Search
Direct
+ Search
+ Customer
−2.5
−3.6
+0.9
−2.4
+ Seller
+5.2
+1.8
+5.9
+1.1
+ Product
+5.5
+2.8
+5.7
+1.7
+ All
+5.3
+3.3
+7.0
+6.6
Table 3: Expert-guided research reports. Δ WCS from expert-curated reports covering the customer, seller, product, or all three. Results are relative to each configuration’s no-report baseline. All results reported as averages over 3 runs.
Model
N -way Acc. (%)
Email-Succ. WCS
Story-Agg. WCS
Claude Sonnet 4.6
45.8
61.11
55.80
GPT-5.4
40.5
50.87
44.32
GPT-5.4-mini
39.0
48.17
44.63
GPT-4o
37.0
42.90
35.42
GPT-4o-mini
37.0
42.39
37.46
STORM
36.2
35.76
42.51
Table 4: Discriminative N -way accuracy ( N=5 : one successful email vs. four same-industry unsuccessful cold outbounds), for the web-search LLMs and the deep-research agents, alongside their WCS on enterprise emails and success stories.
Figure 5: Token usage vs. performance on SDR-Bench. Each point is a configuration; the x -axis is total tokens per query (log scale), the y -axis is WCS, and bubble area encodes inference cost per query.
Appendix figures & tables8 assets
Supplementary material from the paper’s appendix.
Appendix
Filtration Criteria
Count
Domains for companies with > $1B revenue
∼ 30k
B2B companies with > $1B revenue
12,080
Companies whose URLs were discovered
3,500
Total webpages found
∼ 7M
Candidate success story URLs
∼ 400k
After Qwen content filter (listicle/parent/ generic/no-date pages removed)
∼ 60k
Appendix
Table 5: Filtration criteria and surviving counts for the public data collected to build SDR-Bench.
Metric / Artifact Category
Healthcare
Tech
Number of SDRs
3
124
Total Emails Collected
48,150
609,191
Deduplication
31,034
186,379
Sales Outreach Emails
24,506
90,809
Successful Outreach (Call Scheduled)
354
13,236
Appendix
Table 6: Processing of Enterprise Sales Email Data
Figure 6: Personalization in actual sales emails: SDRs adapt the same product positioning across recipients with distinct needs and pain points.
TP
FP
FN
Precision
Recall
F1
138
11
3
0.92
0.97
0.95
Appendix
Table 7: Human evaluation of LLM-extracted pitch points on 30 customer success stories, assessing precision (factual consistency, hallucination flagging) and recall (missed pitch points).
Model
Mode
Prompt
Compl.
Cost
WCS
Tok.
Tok.
($)
STORM
Search
29k
6.3k
0.135
42.51
ODR
Search
66k
8.6k
0.250
33.53
Claude Sonnet 4.6
Search
79k
2.2k
0.270
55.80
Direct
0.3k
1.2k
0.019
49.88
GPT-5.4-mini
Search
7.6k
0.7k
0.009
44.63
Appendix
Table 8: Per-query token usage, inference cost, and WCS on the SDR-Bench evaluation set. Search = temporally-constrained web search; Direct = no tool use. Deep-research agents are search-only. Token counts are mean prompt/completion tokens per query; costs use public API list prices at evaluation time. The deep-research pipelines (STORM, ODR) consume one to two orders of magnitude more tokens than the LLM + search baselines for comparable or lower WCS.
Figure 7: Qualitative example of the Coverage Judge: ground-truth pitch points matched against the agent’s generated pitch points and scored on the 0 – 5 rubric of Appendix A.4 , illustrating how partial topic matches are separated from strategic bullseyes.
Model
Mean WCS
95% CI
Claude Sonnet 4.6
0.5580
[0.5238, 0.5906]
GPT-5.4-mini
0.4488
[0.4265, 0.4700]
GPT-5.4
0.4457
[0.4216, 0.4683]
STORM
0.4251
[0.4003, 0.4517]
GPT-4o-mini
0.3767
[0.3567, 0.3977]
Qwen-2.5-72B
0.3684
[0.3478, 0.3878]
Appendix
Table 9: Bootstrap estimates of WCS on the SDR-Bench evaluation set ( 1,000 resamples), with per-configuration means and 95% confidence intervals. The weaker GPT-family and Qwen intervals overlap (the personalization plateau), while Claude Sonnet 4.6 separates clearly above the rest.
Figure 8: SDR-Bench: Distribution of the count of success stories across different industries, complementing the company-level distribution in Figure 4 . The corpus spans a broad range of sectors, with technology, manufacturing, and energy the most represented.